Predicted to enable ATP hydrolysis activity and single base insertion or deletion binding activity. Predicted to contribute to MutSalpha complex binding activity and single-stranded DNA binding activity. Involved in positive regulation of isotype switching to IgA isotypes; positive regulation of isotype switching to IgG isotypes; and somatic hypermutation of immunoglobulin genes. Acts upstream of or within mismatch repair and somatic recombination of immunoglobulin gene segments. Part of MutLalpha complex. Is expressed in cerebellum; lower urogenital tract; reproductive system; retina; and urethra epithelium. Human ortholog(s) of this gene implicated in Lynch syndrome; hereditary nonpolyposis colorectal cancer type 4; mismatch repair cancer syndrome; ovarian cancer; and urinary bladder cancer. Orthologous to human PMS2 (PMS1 homolog 2, mismatch repair system component). [provided by Alliance of Genome Resources, Apr 2022]