DNA Repair and Recombination

Question 1

What are the the most common kinds of DNA base lesions?

Answer 1

Alkylation, Deamination, Oxidation

Question 2

Ways to generate GC->AT mismatch

Answer 2

Replication of GU or GT mismatch caused by m5C converting to T or Cytosine turning to uracil, O6 methyl guanine

Question 3

Ways to generate AT->GC mismatch

Answer 3

Hypoxanthine (Deaminated Adenine) pairing with C

Question 4

What the three most common kinds of Deamination lesions?

Answer 4

Question 5

Describe the Mismatch Recognition and repair pathway in ecoli, what are are the roles of MutS MutL MutH and ATP?

Answer 5

Question 6

RecBCD

Answer 6

Eznyme with helicase and nuclease activity generates 3’ terminal ss DNA needed to start homologous recombination

Question 7

Rec A

Answer 7

coats ssDNA forming a filament. Promotes strand exchange between two DNAs Involved in many steps of HR

analog of Rad51 in eukaryotes

Question 8

RuvA-RuvB

Answer 8

Promotes migration of Holliday intermediate

Question 9

Ruv C

Answer 9

cleaves the holliday intermediate

Question 10

Describes the Steps of VDJ Recombination, what enzymes are important

Answer 10

two double strand breaks made by RAG proteins

discard DNA between the DS breaks

join remaining ends through NHEJ

Question 11

Give and Example of Site-Specific recombination what enzymes does it use

Answer 11

bacteriophage lamda cleaves at attachment site sequences and uses recombinase to break and rejoin

sequences of the DNA