MutL_Trans_hPMS1_like: transducer domain, having a ribosomal S5 domain 2-like fold, found in proteins similar to human PSM1 (hPSM1) and yeast MLH2. hPSM1 and yMLH2 are members of the DNA mismatch repair (MutL/MLH1/PMS2) family. This transducer domain is homologous to the second domain of the DNA gyrase B subunit, which is known to be important in nucleotide hydrolysis and the transduction of structural signals from ATP-binding site to the DNA breakage/reunion regions of the enzymes. PMS1 forms a heterodimer with MLH1. The MLH1-PMS1 complex functions in meiosis. Loss of yMLH2 results in a small but significant decrease in spore viability and a significant increase in gene conversion frequencies. A role for hMLH1-hPMS1 in DNA mismatch repair has not been established. Mutation in hMLH1 accounts for a large fraction of Lynch syndrome (HNPCC) families, however there is no convincing evidence to support hPMS1 having a role in HNPCC predisposition.