Mechanistic insight into the substrate specificity of 1,2-beta-oligoglucan phosphorylase from Lachnoclostridium phytofermentansNakajima, M., Tanaka, N., Furukawa, N., Nihira, T., Kodutsumi, Y., Takahashi, Y., Sugimoto, N., Miyanaga, A., Fushinobu, S., Taguchi, H., Nakai, H.
(2017) Sci Rep 7: 42671-42671
- PubMed: 28198470
- DOI: 10.1038/srep42671
- Primary Citation of Related Structures:
- PubMed Abstract:
Glycoside phosphorylases catalyze the phosphorolysis of oligosaccharides into sugar phosphates. Recently, we found a novel phosphorylase acting on β-1,2-glucooligosaccharides with degrees of polymerization of 3 or more (1,2-β-oligoglucan phosphorylas ...
Glycoside phosphorylases catalyze the phosphorolysis of oligosaccharides into sugar phosphates. Recently, we found a novel phosphorylase acting on β-1,2-glucooligosaccharides with degrees of polymerization of 3 or more (1,2-β-oligoglucan phosphorylase, SOGP) in glycoside hydrolase family (GH) 94. Here, we characterized SOGP from Lachnoclostridium phytofermentans (LpSOGP) and determined its crystal structure. LpSOGP is a monomeric enzyme that contains a unique β-sandwich domain (Ndom1) at its N-terminus. Unlike the dimeric GH94 enzymes possessing catalytic pockets at their dimer interface, LpSOGP has a catalytic pocket between Ndom1 and the catalytic domain. In the complex structure of LpSOGP with sophorose, sophorose binds at subsites +1 to +2. Notably, the Glc moiety at subsite +1 is flipped compared with the corresponding ligands in other GH94 enzymes. This inversion suggests the great distortion of the glycosidic bond between subsites -1 and +1, which is likely unfavorable for substrate binding. Compensation for this disadvantage at subsite +2 can be accounted for by the small distortion of the glycosidic bond in the sophorose molecule. Therefore, the binding mode at subsites +1 and +2 defines the substrate specificity of LpSOGP, which provides mechanistic insights into the substrate specificity of a phosphorylase acting on β-1,2-glucooligosaccharides.
Department of Biotechnology, The University of Tokyo, Tokyo, Japan.,Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan.,Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan.,Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan.,Graduate School of Science &Technology, Niigata University, Niigata, Japan.