RNR polimerazės III promotoriai
description
Transcript of RNR polimerazės III promotoriai
1
2
3
4
5
6
RNR polimerazės III promotoriai
Jungiasi TFIIIA
Jungiasi TFIIIC
Jungiasi TFIIIC
Jungiasi TFIIIC
TFIIIA ir TFIIIC padeda prisjungti TFIIIB transkripcijos faktoriui
7
RNR polimerazės II promotoriai
Šis promotorius dažniausiai naudojamas embrioninio
vystymosi metu
8
9
10
11
12
Kompleksą gali sudaryti virš 85
polipeptidų
13
14
• 1. Covalent modification of histones– Amino terminals of histones are modified in various ways
• Acetylation; phosphorylation; methylation
Adds acetyl groups, thereby loosening the interaction
between histones and DNA
Removes acetyl groups, thereby restoring a tighter interaction
15
16
• 2. ATP-dependent chromatin remodeling– The energy of ATP is used to alter the structure of
nucleosomes and thus make the DNA more accessible
Proteins are members of the SWI/SNF family
Acronyms refer to the effects on yeast when these enzyme are
defectiveMutants in SWI are defective in
mating type switching
Mutants in SNF are sucrose non-fermenters
These effects may significantly alter gene expression
17
Skirtingų organizmų SWI/SNF kompleksai
18
Chromatino surinkimo ir transkripcinės aktyvacijos, dalyvaujant SWI–SNF, modelis