Modificações Pós-transcricionais (Processamento de RNA)

Descrição Geral

Transcrição

A informação genética do DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure é copiada para o RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure mensageiro ( mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure).

• Neste processo, o mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure é sintetizado do terminal 5′ para o terminal 3′.
• A transcrição inicial é conhecida como RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure nuclear heterogéneo (hnRNA) ou pré-mRNA.

Modificações

As transcrições primárias, ou produtos imediatos da transcrição, sofrem alterações para se tornarem biologicamente funcionais.

• mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure:
  • Procariontes: A maioria dos mRNAs primários não tem modificações.
  • Eucariontes: O transcrito sintetizado de mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure (ou hnRNA) é processado antes de sair do núcleo.
    • Adição do cap 5′
    • Adição da cauda 3′ de poli-A
    • Splicing
  • A modificação de hnRNA produz mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure maturado, que é transportado para o citoplasma através de poros nucleares.
  • Em alguns casos, a edição de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure ocorre com modificações de bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance, criando uma sequência diferente daquela copiada do DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure.
  • Uma sequência diferente de mRNA produz uma proteína diferente; isto varia da velha hipótese de “um gene—um polipéptido”.
• RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de transferência ( tRNA tRNA The small RNA molecules, 73-80 nucleotides long, that function during translation (translation, genetic) to align amino acids at the ribosomes in a sequence determined by the mRNA (RNA, messenger). There are about 30 different transfer rnas. Each recognizes a specific codon set on the mRNA through its own anticodon and as aminoacyl trnas (RNA, transfer, amino Acyl), each carries a specific amino acid to the ribosome to add to the elongating peptide chains. RNA Types and Structure) e RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure ribossomal ( rRNA rRNA The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. RNA Types and Structure):
  • Moléculas estruturais que não são traduzidas
  • Ambos têm pré-tRNA e pré-rRNA que sofrem processamento.

Adição do Cap 5′ e da Cauda 3′ de Poli-A

Cap 5′

7-Metilguanosina (resíduo de guanilil metilado) é adicionado à extremidade 5′ do hnRNA via:

• Remoção do grupo fosfato da ponta no terminal 5′ por RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure trifosfatase
• Transferência de monofosfato de guanosina (GMP pela sigla em inglês) do grupo trifosfato de guanosina pela guanilil transferase
• Metilação da guanina pela guanina-7-metiltransferase (grupo metil de S-adenosilmetionina( SAM SAM Anterior displacement of the mitral valve during systole. Hypertrophic Cardiomyopathy))

Funções:

• Evita a degradação pela exonuclease
• Sequência de reconhecimento para tradução

Cauda 3′ de Poli-A

50 a 250 resíduos de adenilil (AMP pela sigla em inglês) são adicionados à extremidade 3′ do hnRNA via:

• Corte de cerca de 20 nucleótidos a jusante de uma sequência de reconhecimento AAUAA
• Adição (e extensão até 250 nucleotídeos) de cauda de poli-A (gerada a partir de ATP) pela polimerase de poli-A

Função:

• Evita a degradação no citosol por exoribonucleases 3′
• Estabiliza o mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure

Splicing Heterogéneo de RNA Nuclear

Exões e intrões

RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure heterogéneo nuclear (pré-mRNA) contém:

• Secções codificantes chamadas exões (sequências expressas)
• Secções não codificantes chamadas intrões (sequências intervenientes)

Processamento:

• O hnRNA necessita de processamento (splicing) para produzir o mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure com as devidas sequências de codificação.
• Ocorre na maioria dos genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure eucarióticos, mais MAIS Androgen Insensitivity Syndrome frequentemente no mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure

Splicing

• Remoção de intrões do hnRNA/pré-mRNA, simultaneamente à ligação de exões, para formar mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure maturado
• O processo envolve hnRNA e componentes adicionais:
  • Pequenas ribonucleoproteínas nucleares (que são constituídas por pequenos RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure nucleares (snRNA) e proteínas)
  • Outras proteínas de ligação
• Junções onde ocorre a reação de splicing:
  • Locais do splicing:
    • Áreas onde são feitos cortes entre o exão e o intrão
    • As sequências base identificam estes locais, um no lado 5′ (início do intrão) e o outro no lado 3′ (fim do intrão).
    • Sítio 5’/sítio do dador splicing: GU invariável
    • Sítio 3’/sítio do aceitador de splicing: AG AG Metabolic Acidosis invariável
  • Local da ramificação: localizado a montante do sítio 3′.
• Mecanismo:
  1. Pequenas ribonucleoproteínas nucleares reconhecem os locais de splicing e o local da ramificação devido às sequências base no hnRNA.
  2. hnRNA, pequenas ribonucleoproteínas nucleares e outras proteínas combinam-se para formar o spliceossoma.
  3. O complexo spliceossoma faz um corte no local de splicing 5′ dador (ocorre através de um ataque nucleofílico por um resíduo de adenilil no local da ramificação).
  4. O agora livre terminal 5′ do intrão liga-se ao local da ramificação, formando uma estrutura em loop ou laço.
  5. O local de splicing 3′ é reconhecido, e o segundo corte ocorre lá. Segue-se a libertação do laço, e os 2 exões são unidos para formar o RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure maturado
• Ocorre simultaneamente com o cap 5′ e as modificações da cauda 3′ de hnRNA
• Patologias relacionadas:
  • β-talassémia:
    • Contém defeitos no splicing do mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure do gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics β-globulina
    • Mutações homozigóticas significativas (talassémia major) resultam em anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types dependente de transfusão
  • Atrofia muscular espinhal:
    • Falta de funcionamento do gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics SMN1 Smn1 Spinal Muscular Atrophy devido a mutação
    • O SMN2 Smn2 Spinal Muscular Atrophy restante é incapaz de compensar devido ao defeito ao nível de splicing pré-MRNA (omissão do exão 7).

Splicing alternativo

• Splicing diferencial de uma sequência hnRNA
• Mecanismos:
  • Os exões são seletivamente incluídos ou excluídos.
  • São utilizados locais alternativos de dadores 5′ ou aceitadores 3′.
  • Os locais de poliadenilação podem ser diferentes.
• Até 95% dos genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure multiexão sofrem splicing alternativo (SA) para codificar proteínas com diferentes funções celulares.
• SA é uma etapa de regulação de resposta rápida necessária para uma síntese de proteínas aperfeiçoada, e assim determinar os fenótipos celulares e as taxas de proliferação.
• Cerca de 15% das doenças hereditárias e cancros estão reportados como sendo associados ao SA.
• Diferentes combinações de exões podem levar à criação de diferentes proteínas relacionadas a partir do mesmo hnRNA:
  • Moléculas de imunoglobulina ( genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure para cadeias pesadas possuem exões relacionados a subtipos individuais)
  • Variantes de tropomiosina no músculo
  • Recetores de dopamina no cérebro (recetores D2 com 2 isoformas)

Edição de RNA

Geralmente, a sequência de DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure é refletida no mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure maturado. A alteração da sequência ou edição do RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure é uma exceção.

Definição

• Uma alteração na informação codificante após a transcrição resulta numa sequência de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure diferente da sequência do seu DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure original.
• Acredita-se que contribui para a regulação genética
• Processos:
  • Mudanças de bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance
  • Exclusão de bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance
  • Inserções de bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance

Mudanças de bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance

Edição “C-para-U”:

• Gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics da apolipoproteína B(apoB): Os mesmos códigos genéticos para ApoB100 (sintetizado no fígado) e ApoB48 (sintetizado no intestino).
• No intestino:
  • Desaminação da citosina (para uracilo) catalisada pela enzima citidina desaminase.
  • Codão CAA (citidina–adenina–adenina) (no mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure) → UAA (uridina–adenina–adenina), um sinal de fim ou um codão de paragem
• Como resultado desta edição:
  • ApoB100 é uma proteína de 100 kDa constituída por 4536 aminoácidos.
  • ApoB48 é uma proteína mais MAIS Androgen Insensitivity Syndrome curta de 48 kDa constituída por 2152 aminoácidos.
  • A mudança produz ApoB48, que não tem o domínio C-terminal de ApoB100 (responsável pela ligação dos recetores LDL).

Edição “A-para-I”:

• Afeta os substratos de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de cadeia dupla
• Desaminação da adenina (a hipoxantina) catalisada por ADAR (adenosina desaminase que atua no RNA)
• Adenosinas convertidas em inosinas, o que leva a substituições de bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance A para G
• Gera locais de splicing alternativo

Inserções/exclusões

• Ocorre em tripanossomas e protozoários relacionados, afetando o mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure mitocondrial
• Envolve adição ou eliminação de uridina

RNA Ribossomal e Processamento de RNA de Transferência

RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure Ribossomal

• Em procariontes:
  • Como estudado em Escherichia coli Escherichia coli The gram-negative bacterium Escherichia coli is a key component of the human gut microbiota. Most strains of E. coli are avirulent, but occasionally they escape the GI tract, infecting the urinary tract and other sites. Less common strains of E. coli are able to cause disease within the GI tract, most commonly presenting as abdominal pain and diarrhea. Escherichia coli, existem 3 tipos de rRNA rRNA The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. RNA Types and Structure (5S, 16S e 23S) que têm transcrições primárias policistrónicas.
  • Processamento inicial da transcrição via clivagem endonucleolítica por RNases → pré-rRNA
  • As extremidades 5′ e 3′ do pré-RNA são então cortadas por outro conjunto de RNases.
  • A metilação ocorre durante a montagem de ribossomas para proteger contra a degradação.
• Em eucariontes, a transcrição primária é uma grande molécula precursora 45S:
  • Contém moléculas de rRNA rRNA The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. RNA Types and Structure (28S, 18S e 5,8S) com sequências de distanciadoras no meio
  • Processado no nucléolo:
    • Por metilação em vários locais (facilitada por pequenos RNAs nucleolares (snoRNA))
    • Posteriormente, por corte do RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure
  • O quarto tipo de rRNA rRNA The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. RNA Types and Structure, 5S, é processado separadamente.
  • Os rRNA rRNA The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. RNA Types and Structure maturados resultantes, que se associam com outras proteínas, tornam-se o suporte das unidades ribossómicas no citoplasma.
• Alguns rRNA rRNA The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. RNA Types and Structure eucarióticos têm intrões, e nesses, os rRNA rRNA The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. RNA Types and Structure pré-rRNAs fazem auto-splicing (agem como ribozimas).

RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de transferência

• O RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de transferência é um polinucleótido único composto por uma média de 75 nucleótidos com características únicas:
  • Devido ao dobramento (folding) distinto, as extremidades 5′ e 3′ compõem o braço aceitador.
  • A extremidade 3′ também tem uma sequência CCA (citosina-citosina-adenina).
  • Tem bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance modificadas como inosina, dihidrouridina, e pseudouridina
• O precursor tRNA tRNA The small RNA molecules, 73-80 nucleotides long, that function during translation (translation, genetic) to align amino acids at the ribosomes in a sequence determined by the mRNA (RNA, messenger). There are about 30 different transfer rnas. Each recognizes a specific codon set on the mRNA through its own anticodon and as aminoacyl trnas (RNA, transfer, amino Acyl), each carries a specific amino acid to the ribosome to add to the elongating peptide chains. RNA Types and Structure contém:
  • Nucleótidos extra nas extremidades 3′ e 5′.
  • Intrões
• O processamento envolve:
  • A remoção dos nucleótidos e intrões extra
  • Modificação de bases Bases Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. Acid-Base Balance padrão (como a metilação e a desaminação)
  • Utiliza RNase P (uma ribozima) para formar a extremidade 5′.
  • A adição de CCA no final da extremidade 3′ por tRNA tRNA The small RNA molecules, 73-80 nucleotides long, that function during translation (translation, genetic) to align amino acids at the ribosomes in a sequence determined by the mRNA (RNA, messenger). There are about 30 different transfer rnas. Each recognizes a specific codon set on the mRNA through its own anticodon and as aminoacyl trnas (RNA, transfer, amino Acyl), each carries a specific amino acid to the ribosome to add to the elongating peptide chains. RNA Types and Structure nucleotidiltransferase