(condensed) dna repair

Question 1

name of the subunit which does proofreading, and which polymerases have it

Answer 1

ε & δ
exonuclease site

Question 2

BER- when does it happen

Answer 2

spontaneous damage like deamination and methylation of bases which don’t distort the helix

Question 3

BER- vague mechanism

Answer 3

nick generated, then depending on if its SP or LP either a base is cut out or a flap is formed, and ligation from there

Question 4

NER- when does it happen

Answer 4

distortion e.g. from thymidine dimer formation

Question 5

NER- how does it work

Answer 5

excision of a nucleotide, filling in the gap using polymerases (can also be transcription-coupled)

Question 6

MMR- when does it happen

Answer 6

specifically base mismatches e..g A pairing w T

Question 7

MMR mechanism

Answer 7

excision around the mismatch on the daughter strand, leaving a gap which is filled in

Question 8

3 proteins to remmeber for NHEJ

Answer 8

Ku70/80
DNA PKcs
Lig4
maybe Artemis

Question 9

3 proteins for A-NHEJ

Answer 9

MRN complex
PARP
Lig3

Question 10

invading protein for HR

Answer 10

Rad51

Question 11

how is HR chosen

Answer 11

MRN displaces Ku

Question 12

3 HR pathways

Answer 12

single-strand annealing
DHJ
synthesis-dependent strand-annealing