Identification of N-acetylhexosamine 1-kinase in the complete lacto-N-biose I/galacto-N-biose metabolic pathway in Bifidobacterium longum.
We have determined the functions of the enzymes encoded by the lnpB, lnpC, and lnpD genes, located downstream of the lacto-N-biose phosphorylase gene (lnpA), in Bifidobacterium longum JCM1217. The lnpB gene encodes a novel kinase, N-acetylhexosamine 1-kinase, which produces N-acetylhexosamine 1-phosphate; the lnpC gene encodes UDP-glucose hexose 1-phosphate uridylyltransferase, which is also active on N-acetylhexosamine 1-phosphate; and the lnpD gene encodes a UDP-glucose 4-epimerase, which is active on both UDP-galactose and UDP-N-acetylgalactosamine. These results suggest that the gene operon lnpABCD encodes a previously undescribed lacto-N-biose I/galacto-N-biose metabolic pathway that is involved in the intestinal colonization of bifidobacteria and that utilizes lacto-N-biose I from human milk oligosaccharides or galacto-N-biose from mucin sugars.
Nishimoto
Mamoru
M
National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
Kitaoka
Motomitsu
M
D000117:Acetylglucosamine / Q000031:analogs & derivatives* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001644:Bifidobacterium / Q000201:enzymology* / Q000235:genetics; D004187:Disaccharides / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006595:Hexosamines / Q000378:metabolism*; D008969:Molecular Sequence Data; D009876:Operon; D010770:Phosphotransferases / Q000378:metabolism*; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D004187:Disaccharides; D006595:Hexosamines; C056853:6-O-galactopyranosylgalactose; C033398:galactosyl-1,3-N-acetylglucosamine; D010770:Phosphotransferases; D000117:Acetylglucosamine