Gene Proteins and Functions - Eukaryotic DNA repair, Introns, mRNA processing, RNAi

Question 1

XPC and Rad23b

Answer 1

Recognises bulky lesions, recruits DDB1 and DDB2 - for GG-NER

Question 2

CSA and CSB

Answer 2

Attracts more NER proteins, are repair coupling factors? For TC-NER

Question 3

XPB and XPD, and TFIIH is also there

Answer 3

Separate strands at damage site, recruit XPF and XPG

Question 4

XPF and XPG

Answer 4

Cut upstream and downstream of lesion

Question 5

DDB1 and DDB2

Answer 5

Separate strands at damage site - for GG-NER

Question 6

RPA

Answer 6

Single stranded binding proteins that keep the NER region single stranded

Question 7

Repair synthesis for NER is done by:

Answer 7

Pol delta and DNA ligase

Question 8

DNA glycosylase - BER

Answer 8

Removes damaged base

Question 9

APE1 (with or without phosphodiesterase)

Answer 9

AP endonuclease to cleave out DNA backbone/sugar

Question 10

Long patch proteins

Answer 10

PCNA, Pol delta, Pol epsilon, Lig1, WRN + Fen1 (these last two for strand displacement)

Question 11

Short patch proteins

Answer 11

Pol beta, Lig3, XRCC1

Question 12

TFIIH + U1snRNA - introns

Answer 12

Facilitate nearby promoter function [PROMOTER CLEARANCE]

Question 13

U snRNP + TAT-SF1

Answer 13

Improve processivity [PROMOTER CLEARANCE]

Question 14

TAT-SF1 + pTEFb

Answer 14

Phosphorylate CTD of pol II [PROMOTER CLEARANCE]

Question 15

ADAR Enzymes

Answer 15

Adenine deaminases for RNA, convert dsRNA adenine into inosine (A -> G)

Question 16

Magoh and Y14

Answer 16

Subcellular localisation proteins leftover from splicing maybe?

Question 17

Dicer

Answer 17

Acts on long dsRNA to produce siRNAs

Question 18

RISC

Answer 18

RNA induced silencing complex, incl. Argo proteins, nucleases, RNA binders - degrades sense RNA strand, leaving antisense which binds complementary RNA sequence

Question 19

E. coli Ada enzyme

Answer 19

Direct repair, removes alkyl groups, methyl groups

Question 20

E. coli (some eukaryotes) DNA photolyase / photoreactivation

Answer 20

Direct repair, the enzyme binds thymine dimers and returns them to monomeric nucleotides