FIGURE 2.

DNA alters solvent accessibility for regions of MutS. A, change in percent deuteration of individual peptides from MutS bound to a 71-bp DNA duplex containing a central GT mispair and MutS at 300 s. Green bars that span the indicated sequence on the x axis indicate peptides measured in both samples. Positive and negative y axis values indicate enhancement and protection from deuterium exchange, respectively, caused by addition of the DNA substrate. Regions of substantial protection are boxed. B, kinetics of deuteron incorporation for a representative peptide of MutS in the presence (red) and absence (black) of DNA for each region boxed in A. C, regions of protection upon DNA addition (blue) mapped onto the ribbon diagram of MutS.