2017年2月15日
Mechanistic insight into the substrate specificity of 1,2-β-oligoglucan phosphorylase from Lachnoclostridium phytofermentans.
Scientific reports
- 巻
- 7
- 号
- 開始ページ
- 42671
- 終了ページ
- 42671
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1038/srep42671
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.
- リンク情報
- ID情報
-
- DOI : 10.1038/srep42671
- PubMed ID : 28198470
- PubMed Central 記事ID : PMC5309861