4B9Z

Crystal Structure of Agd31B, alpha-transglucosylase, complexed with Acarbose

4B9Z の概要

• エントリーDOI: 10.2210/pdb4b9z/pdb
• 関連するPDBエントリー: 4B9Y 4BA0
• 関連するBIRD辞書のPRD_ID: PRD_900007
• 分子名称: ALPHA-GLUCOSIDASE, PUTATIVE, ADG31B, 4,6-dideoxy-4-{[(1S,4R,5S,6S)-4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl]amino}-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, SULFATE ION, ... (7 entities in total)
• 機能のキーワード: hydrolase
• 由来する生物種: CELLVIBRIO JAPONICUS
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 94762.58

構造登録者

Larsbrink, J.,Izumi, A.,Hemsworth, G.R.,Davies, G.J.,Brumer, H. (登録日: 2012-09-09, 公開日: 2012-11-14, 最終更新日: 2024-10-23)

主引用文献

Larsbrink, J.,Izumi, A.,Hemsworth, G.R.,Davies, G.J.,Brumer, H.
Structural Enzymology of Cellvibrio Japonicus Agd31B Reveals Alpha-Transglucosylase Activity in Glycoside Hydrolase Family 31
J.Biol.Chem., 287:43288-, 2012

PubMed Abstract: The metabolism of the storage polysaccharides glycogen and starch is of vital importance to organisms from all domains of life. In bacteria, utilization of these α-glucans requires the concerted action of a variety of enzymes, including glycoside hydrolases, glycoside phosphorylases, and transglycosylases. In particular, transglycosylases from glycoside hydrolase family 13 (GH13) and GH77 play well established roles in α-glucan side chain (de)branching, regulation of oligo- and polysaccharide chain length, and formation of cyclic dextrans. Here, we present the biochemical and tertiary structural characterization of a new type of bacterial 1,4-α-glucan 4-α-glucosyltransferase from GH31. Distinct from 1,4-α-glucan 6-α-glucosyltransferases (EC 2.4.1.24) and 4-α-glucanotransferases (EC 2.4.1.25), this enzyme strictly transferred one glucosyl residue from α(1→4)-glucans in disproportionation reactions. Substrate hydrolysis was undetectable for a series of malto-oligosaccharides except maltose for which transglycosylation nonetheless dominated across a range of substrate concentrations. Crystallographic analysis of the enzyme in free, acarbose-complexed, and trapped 5-fluoro-β-glucosyl-enzyme intermediate forms revealed extended substrate interactions across one negative and up to three positive subsites, thus providing structural rationalization for the unique, single monosaccharide transferase activity of the enzyme.

PubMed: 23132856
DOI: 10.1074/JBC.M112.416511

実験手法

X-RAY DIFFRACTION (2 Å)