Skip to main content
. Author manuscript; available in PMC: 2017 Feb 1.
Published in final edited form as: DNA Repair (Amst). 2015 Dec 2;38:110–116. doi: 10.1016/j.dnarep.2015.11.011

Fig. 1. MMR proteins create mutations at A:T bp during SHM.

Fig. 1

AID deaminates cytosine to uracil in immunoglobulin variable region DNA and generates a U:G mismatch that is recognized by the MSH2-MSH6 heterodimer. A single-strand DNA gap is produced at the mismatch by EXO1 and an unknown nick instigator. Monoubiquitinated PCNA homotrimer recruits the error-prone DNA pol η to fill in the gap, copying the original T with a G instead of an A. DNA replication results in the G:T mismatch being permanently affixed in one of the two daughter cells as a mutation to G:C.