Nishimoto Mamoru, Kitaoka Motomitsu
National Food Research Institute, Japan.
Biosci Biotechnol Biochem. 2007 Jun;71(6):1587-91. doi: 10.1271/bbb.70064.
Two lacto-N-biose phosphorylase (LNBP) isozyme genes were cloned from Bifidobacterium bifidum JCM1254. Alignment of the amino acid sequences of LNBP and its homologs identified 24 completely conserved acidic amino acid residues. All single mutants of Bifidobacterium longum LNBP at residues other than D313N retained considerable activity, suggesting that Asp313 is the putative proton donor residue in LNBP.
从两歧双歧杆菌JCM1254中克隆出两个乳糖 - N - 二糖磷酸化酶（LNBP）同工酶基因。LNBP及其同源物的氨基酸序列比对确定了24个完全保守的酸性氨基酸残基。长双歧杆菌LNBP除D313N位点外的所有单突变体都保留了相当的活性，这表明Asp313是LNBP中假定的质子供体残基。
