Chitobiose phosphorylase from Vibrio proteolyticus, a member of glycosyl transferase family 36, has a clan GH-L-like (alpha/alpha)(6) barrel fold.
Vibrio proteolyticus chitobiose phosphorylase (ChBP) belongs to glycosyl transferase family 36 (GT-36), and catalyzes the reversible phosphorolysis of chitobiose into alpha-GlcNAc-1-phosphate and GlcNAc with inversion of the anomeric configuration. As the first known structures of a GT-36 enzyme, we determined the crystal structure of ChBP in a ternary complex with GlcNAc and SO(4). It is also the first structures of an inverting phosphorolytic enzyme in a complex with a sugar and a sulfate ion, and reveals a pseudo-ternary complex structure of enzyme-sugar-phosphate. ChBP comprises a beta sandwich domain and an (alpha/alpha)(6) barrel domain, constituting a distinctive structure among GT families. Instead, it shows significant structural similarity with glycoside hydrolase (GH) enzymes, glucoamylases (GH-15), and maltose phosphorylase (GH-65) in clan GH-L. The structural similarity reported here, together with distant sequence similarities between ChBP and GHs, led to the reclassification of family GT-36 into a novel GH family, namely GH-94.
Hidaka
Masafumi
M
Department of Biotechnology, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Honda
Yuji
Y
Kitaoka
Motomitsu
M
Nirasawa
Satoru
S
Hayashi
Kiyoshi
K
Wakagi
Takayoshi
T
Shoun
Hirofumi
H
Fushinobu
Shinya
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001665:Binding Sites; D002241:Carbohydrates / Q000737:chemistry; D018360:Crystallography, X-Ray; D019281:Dimerization; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry; D005964:Glucosyltransferases / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000737:chemistry; D016695:Glycosyltransferases / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D012984:Software; D013379:Substrate Specificity; D013431:Sulfates / Q000737:chemistry; D014733:Vibrio / Q000201:enzymology*
D001426:Bacterial Proteins; D002241:Carbohydrates; D013431:Sulfates; D016695:Glycosyltransferases; D005964:Glucosyltransferases; C415834:N,N'-diacetylchitobiose phosphorylase; D017351:N-Acetylglucosaminyltransferases; C021535:maltose phosphorylase; D006026:Glycoside Hydrolases; D005087:Glucan 1,4-alpha-Glucosidase