Details

Autor(en) / Beteiligte

• Nakajima, Masahiro
• Tanaka, Nobukiyo
• Furukawa, Nayuta
• Nihira, Takanori
• Kodutsumi, Yuki
• Takahashi, Yuta
• Sugimoto, Naohisa
• Miyanaga, Akimasa
• Fushinobu, Shinya
• Taguchi, Hayao
• Nakai, Hiroyuki

Titel

Mechanistic insight into the substrate specificity of 1,2-[beta]-oligoglucan phosphorylase from Lachnoclostridium phytofermentans

Ist Teil von

• Scientific reports, 2017-02, Vol.7, p.42671

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2017

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• 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.