title: Characterization of a bifunctional cytidine 5'-monophosphate N-acetylneuraminic acid synthetase cloned from Streptococcus agalactiae.
abstract: Recombinant CMP-sialic acid synthetase, cloned from Streptococcus agalactiae serotype V strain 2603 V/R, is bifunctional having both CMP-sialic acid synthetase and acetylhydrolase (acylesterase) activities. The enzyme is active over a wide pH range with an optimal CMP-sialic acid synthetase activity at pH 9.0 and an optimal acetylhydrolase activity at pH 8.0. A metal cofactor (either Mg(2+) or Mn(2+)) is required for the CMP-sialic acid synthetase activity but is not for acetylhydrolase activity. Both catalytic functions, however, are impaired by high concentrations of Mn(2+).
authors.affiliation: Department of Chemistry, University of California, Davis, 95616, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Yu
authors.forename: Wesley
authors.initials: W
authors.lastname: Ryan
authors.forename: Hai
authors.initials: H
authors.lastname: Yu
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
mesh_terms: D002384:Catalysis; D003001:Cloning, Molecular; D003067:Coenzymes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D000216:N-Acylneuraminate Cytidylyltransferase / Q000737:chemistry* / Q000235:genetics; D013292:Streptococcus agalactiae / Q000201:enzymology* / Q000235:genetics
chemical_list: D003067:Coenzymes; D008345:Manganese; D000216:N-Acylneuraminate Cytidylyltransferase; D008274:Magnesium