Mismatch Repair and Double Strand Break Repair

Question 1

What is the replication fidelity in E. coli?

Answer 1

10-10 errors per bp (1 in 10 billion bp)

Question 2

What does replication fidelity mean exactly?

Answer 2

This measure indicates the accuracy with which DNA base pairs are replicated and synthesized.

Question 3

What is the name for DNA methylated on only one strand?

Answer 3

Hemimethylated DNA

Question 4

What proteins are involved in prokaryotic mismatch repair?

Answer 4

MutS, MutL, MutH proteins are involved in…

Question 5

What is the main repair pathway for double-strand breaks in non-dividing cells?

Answer 5

Non-homologous end-joining (NHEJ) is the main repair pathway in…

Question 6

What protein binds the Chi sequence in E.coli DSB repair?

Answer 6

RecC

Question 7

What is the function of the MutS-MutL complex in MMR in bacteria?

Answer 7

This protein complex recognizes and binds to mismatched base pairs

Question 8

What is the average distance between hemimethylated nucleotide sites in E. coli DNA?

Answer 8

The average distance between hemimethylated DNA sites is 256 bp

Question 9

Describe the Moving Model of MMR in E. coli.

Answer 9

In this model, the MutS-MutL complex threads through the DNA strand until it finds the MutH complex which is bound at a hemimethylated DNA site.