Cloning of the gene encoding α-methylserine hydroxymethyltransferase from Aminobacter sp. AJ110403 and Ensifer sp. AJ110404 and characterization of the recombinant enzyme

Abstract

Genes encoding α-methylserine hydroxymethyltransferase from Aminobacter sp. AJ110403 and Ensifer sp. AJ110404 were cloned and expressed in Escherichia coli. The purified enzymes were homodimers with a 46-kDa subunit and contained 1 mol/mol-subunit of pyridoxal 5′-phosphate. The V max of these enzymes catalyzing the conversion of α-methyl-L-serine to D-alanine via tetrahydrofolate was 22.1 U/mg (AJ110403) and 15.4 U/mg (AJ110404).