Dogma Central De La Biologia Molecular

El Dogma Central de la Biología Molecular describe un proceso de dos pasos, la transcripción y la traducción, por el cual la información contenida en los genes se transforma en proteínas. ADN ARN proteínas

TRANSCRIPCION

DNA

mRNA Ribosoma TRADUCCION Polipeptido

celula procariotica

Envoltura Nuclear

TRANSCRIPTION

DNA

Pre-mRNA PROCESAMIENTO RNA

mRNA

Ribosoma TRADUCCIONPolipeptido

Eukaryotic cell

TRANSCRIPCION

DNA

mRNA
Ribosoma TRADUCCION Polipeptido

Celula Procariotica

LE 17-3-5

TRANSCRIPTION

DNA

mRNA Ribosome TRANSLATION Polypeptide

Prokaryotic cell

Nuclear envelope

TRANSCRIPTION

DNA

Pre-mRNA RNA PROCESSING

mRNA

Ribosome TRANSLATION Polypeptide

Eukaryotic cell

Gen 2 DNA molecula Gen 1

Gen 3

DNAcadena (templada)

3

5

TRANSCRIPCION

mRNA

5 Codon

3

TRADUCCION

Proteina

Amino acido

Promotor
Unidad Transcripcion

5 3

DNA Punto de iniciacion RNA polimerasa

3 5

Iniciacion

Elongacion
5 3 Unwound DNA RNA transcript Template strand of DNA 3 5

No-templada Cadena devDNA RNA nucleotidos RNA polimerasa

Elongacion
3 3 end Rewound DNA 53 5 RNA transcripto 5 Direccion de transcripcion (“downstream”) 3 5

5

Terminacion
Nuevo RNA

Cadena templado ADN

5 3 5 Completo RNA transcript 3

3 5

LE 17-8
Promoter 5 3 TATA box Start point Eukaryotic promoters 3 5 Template DNA strand Several transcription factors

Transcription factors

5 3

3 5 Additional transcription factors

RNA polymerase IITranscription factors

5 3

5

3 5 RNA transcript

Transcription initiation complex

LE 17-11

RNA transcript (pre-mRNA) 5 Exon 1 Protein Intron Exon 2

snRNA
snRNPs Spliceosome

Other proteins

5

Spliceosome components

Cut-out intron mRNA

5

Exon 1

Exon 2

RNA transcripto (pre-mRNA) 5
Exon 1 Intron Exon 2

Proteina
snRNA snRNPs Otras proteinasSpliceosoma

Spliceosoma

5

componentes Spliceosoma Corte-out intron mRNA

5
Exon 1 Exon 2

Gen DNA
Exon 1 Intron Exon 2 Intron Exon 3

Transcripcion

Procesamiento RNA Traduccion

Dominio 3

Dominio 2 Dominio 1

Polipeptido

LE 17-9

Protein-coding segment

Polyadenylation signal

5
Start codon Stop codon

5 Cap

5 UTR

3 UTR

Poly-A tail

LE17-10

5 Exon Intron
Pre-mRNA 5 Cap

Exon 104

Intron 105

Exon

3
Poly-A tail

1

30

31
Coding segment

146

Introns cut out and exons spliced together

5 Cap 5 UTR

Poly-A tail

1

146
3 UTR

Codón iniciación

Codón

Codón Stop

Guía (no traducido)

Fragmento lectura (traducido)

Cola (no traducido)

LE 17-13

Polypeptide

Amino acidstRNA with amino acid attached Ribosome

tRNA Anticodon

5
mRNA

Codons

3

3 Sitio de union Amino acido 5

Puentes Hydrogeno

Anticodon estructura dos dimensiones 5 3 Sitio de union Amino acido

Puentes Hidrogeno

3 Anticodon Estructura tres dimensiones

5 Anticodon

Simbolo usado

Amino acido

Aminoacil-tRNA sintetasa (enzima)

Pirofosfato Fosfatos tRNAAMP

Aminoacil tRNA (un “activado amino acido”)

sitio P (Sitio ligadura Peptidil-tRNA) sitio E (sitio salida) E Sitio ligadura mRNA P A Sitio A (sitio de ligadura Aminoacyl-tRNA)

Subunidad mayor Subunidad menor

Schematic model showing binding sites

LE 17-5 Second mRNA base

Third mRNA base (3 end)

LE 17-16
tRNA molecules Growing polypeptide Exit tunnel

E P A

Largesubunit

Small subunit 5

3 mRNA Computer model of functioning ribosome P site (Peptidyl-tRNA binding site) E site (Exit site) E mRNA binding site P A

A site (AminoacyltRNA binding site)

Large subunit Small subunit

Schematic model showing binding sites
Growing polypeptide Next amino acid to be added to polypeptide chain E mRNA tRNA 3 Codons Schematic model with mRNA and tRNA...