Characterization of the D-xylulose 5-phosphate/D-fructose 6-phosphate phosphoketolase gene (xfp) from Bifidobacterium lactis.

ABSTRACT: A D-xylulose 5-phosphate/D-fructose 6-phosphate phosphoketolase (Xfp) from the probiotic Bifidobacterium lactis was purified to homogeneity. The specific activity of the purified enzyme with D-fructose 6-phosphate as a substrate is 4.28 Units per mg of enzyme. K(m) values for D-xylulose 5-phosphate and D-fructose 6-phosphate are 45 and 10 mM, respectively. The native enzyme has a molecular mass of 550,000 Da. The subunit size upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis (90,000 Da) corresponds with the size (92,529 Da) calculated from the amino acid sequence of the isolated gene (named xfp) encoding 825 amino acids. The xfp gene was identified on the chromosome of B. lactis with the help of degenerated nucleotide probes deduced from the common N-terminal amino acid sequen

SUBMITTER: Meile L 

PROVIDER: S-EPMC99511 | biostudies-literature | 2001 May

REPOSITORIES: biostudies-literature