Increased catalytic efficiency following gene fusion of bifunctional methionine sulfoxide reductase enzymes from Shewanella oneidensis.

ABSTRACT: Methionine sulfoxide reductase enzymes MsrA and MsrB have complementary stereospecificities that reduce the S and R stereoisomers of methionine sulfoxide (MetSO), respectively, and together function as critical antioxidant enzymes. In some pathogenic and metal-reducing bacteria, these genes are fused to form a bifunctional methionine sulfoxide reductase (i.e., MsrBA) enzyme. To investigate how gene fusion affects the substrate specificity and catalytic activities of Msr, we have cloned and expressed the MsrBA enzyme from Shewanella oneidensis, a metal-reducing bacterium and fish pathogen. For comparison, we also cloned and expressed the wild-type MsrA enzyme from S. oneidensis and a genetically engineered MsrB protein. MsrBA is able to completely reduce (i.e., repair) MetSO in the calcium

SUBMITTER: Chen B 

PROVIDER: S-EPMC2546871 | biostudies-literature | 2007 Dec

REPOSITORIES: biostudies-literature