MutS F36A facilitates efficient infection by G-rich M13 phage. To ask if MutS G4 binding activity influences phage infection success, we examined the abilities of a M13 variant called M13-G (which contains the G4 capable sequence shown in Figure 1H) and its parent molecule (M13mp18) to infect bacteria in the presence or absence of MutS expression. (A) Cartoon depicting plaque assay methodology. MutS proficient (NM522), deficient (NM522 mutS::TN 10 (JW1)) transformed with empty (Mock Vector), or JW1 expressing MutS F36A from “MutS F36A” vector were infected to ask if MutS influences infection efficiency when M13 harbors a G4 competent sequence. Phage infection success for MutS defective strain was measured by counting plaques/plate. (B) Graph depicting results of assay diagrammed in A. Phage infection success for the JW1 MutS defective strain was measured by counting plaques then normalizing to the isogenic MutS proficient strain NM522 (n = 6).