An inverting beta-1,2-mannosidase belonging to glycoside hydrolase family 130 from Dyadobacter fermentans

作者：Nihira Takanori; Chiku Kazuhiro; Suzuki Erika; Nishimoto Mamoru; Fushinobu Shinya; Kitaoka Motomitsu; Ohtsubo Ken'ichi; Nakai Hiroyuki^*

来源：FEBS Letters, 2015, 589(23): 3604-3610.

DOI：10.1016/j.febslet.2015.10.008

• Glycoside hydrolase family 130
• beta-1,2-Mannooligosaccharide
• beta-1,2-Mannosidase

The glycoside hydrolase family (GH) 130 is composed of inverting phosphorylases that catalyze reversible phosphorolysis of beta-D-mannosides. Here we report a glycoside hydrolase as a new member of GH130. Dfer_3176 from Dyadobacter fermentans showed no synthetic activity using alpha-D-mannose 1-phosphate but it released alpha-D-mannose from beta-1,2-mannooligosaccharides with an inversion of the anomeric configuration, indicating that Dfer_3176 is a beta-1,2-mannosidase. Mutational analysis indicated that two glutamic acid residues are critical for the hydrolysis of beta-1,2-mannotriose. The two residues are not conserved among GH130 phosphorylases and are predicted to assist the nucleophilic attack of a water molecule in the hydrolysis of the beta-D-mannosidic bond.

• 出版日期2015-11-30