Download MendeleyMechanistic insight into the substrate specificity of 1,2-beta-oligoglucan phosphorylase from Lachnoclostridium phytofermentans
Nakajima, 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: https://doi.org/10.1038/srep42671
- Primary Citation of Related Structures:
5H3Z, 5H40, 5H41, 5H42 - 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 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.
Organizational Affiliation:
Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan.
