title: Comparison between thymidylate synthase B of Bacillus subtilis ATCC6633 and 168.
abstract: Bacillus subtilis 168 possesses two thymidylate synthase genes: thyA and thyB, encoding for a thermolabile and a thermostable enzyme respectively. B. subtilis ATCC6633 also possesses two thy genes, both producing thermostable enzymes. A comparison of the thymidylate synthase B amino acid sequences from the two strains shows, among others, a Pro to Ala mutation which may affect the dUMP binding site. The apparent Km and Vmax values for dUMP and tetrahydrofolate were determined at a permissive temperature for both enzymes. The kinetic data showed a significant difference in the Km, but not in the Vmax, for dUMP between the two enzymes. The Km and Vmax for tetrahydrofolate were very similar.
mesh_terms: D000409:Alanine / Q000235:genetics*; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D007700:Kinetics; D008969:Molecular Sequence Data; D017354:Point Mutation; D011392:Proline / Q000235:genetics*; D013045:Species Specificity; D013940:Thymidylate Synthase / Q000235:genetics*
chemical_list: D011392:Proline; D013940:Thymidylate Synthase; D000409:Alanine