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Biol321 Molecular Genetics

Handout 6

The central dogma of molecular biology

DNAto

RNAto

Protein

Francis Crick (1958)

Cytoplasm

Nucleus

DNA

RNA

Protein

Replication

Transcription

Translation

Central Dogma Two stages of transcription

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Matrix-Associated Regions

Scaffold Attachment Regions

Euchromatin

50 to 100kb as 30nm

Nuclear matrix

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Modifications determine chromatin structure

Histone DeACetylase

Histone AcetylTransferase

AcCoA

C

O

CHNHCH2C

O

NH... ...CH2CH2CH2CH2NH 3

+

C

O

CHNHCH2 C

O

NH... ...CH2CH2CH2CH2NH

Gly Lys

CCH3

O

CoA

AcPositive charge on amino group No charge on amide group

Histone acetyl transferases

Histone deacetylases

Histones are acetylated and deacetylated

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Nucleosome remodeling, sliding, and transfer

Cis-displacement Trans-displacement

5-Methylcytosine

DNA methyltransferase(DNMT)

De novo vs. maintenance

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Chromatin remodeling complexes

Synthesis of RNA on a DNA template strand

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Promoter, RNA-coding sequence, and terminator regions of a gene

of gene

ORF

+1-1-2-3 +2+3+4

Transcription Process