3W7W

Crystal structure of E. coli YgjK E727A complexed with 2-O-alpha-D-glucopyranosyl-alpha-D-galactopyranose

3W7W の概要

• エントリーDOI: 10.2210/pdb3w7w/pdb
• 関連するPDBエントリー: 3D3I 3W7S 3W7T 3W7U 3W7X
• 分子名称: Uncharacterized protein YgjK, alpha-D-glucopyranose-(1-2)-alpha-D-galactopyranose, CALCIUM ION, ... (5 entities in total)
• 機能のキーワード: gh63, processing alpha-glucosidase i, alpha/alpha barrel, hydrolase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 172828.45

構造登録者

Miyazaki, T.,Ichikawa, M.,Yokoi, G.,Kitaoka, M.,Mori, H.,Kitano, Y.,Nishikawa, A.,Tonozuka, T. (登録日: 2013-03-08, 公開日: 2013-07-17, 最終更新日: 2024-10-30)

主引用文献

Miyazaki, T.,Ichikawa, M.,Yokoi, G.,Kitaoka, M.,Mori, H.,Kitano, Y.,Nishikawa, A.,Tonozuka, T.
Structure of a bacterial glycoside hydrolase family 63 enzyme in complex with its glycosynthase product, and insights into the substrate specificity.
Febs J., 280:4560-4571, 2013

PubMed Abstract: Proteins belonging to glycoside hydrolase family 63 (GH63) are found in bacteria, archaea and eukaryotes. Although the eukaryotic GH63 proteins have been identified as processing α-glucosidase I, the substrate specificities of the bacterial and archaeal GH63 proteins are not clear. Here, we converted a bacterial GH63 enzyme, Escherichia coli YgjK, to a glycosynthase to probe its substrate specificity. Two mutants of YgjK (E727A and D324N) were constructed, and both mutants showed glycosynthase activity. The reactions of E727A with β-D-glucosyl fluoride and monosaccharides showed that the largest amount of glycosynthase product accumulated when galactose was employed as an acceptor molecule. The crystal structure of E727A complexed with the reaction product indicated that the disaccharide bound at the active site was 2-O-α-D-glucopyranosyl-α-D-galactopyranose (Glc12Gal). A comparison of the structures of E727A-Glc12Gal and D324N-melibiose showed that there were two main types of conformation: the open and closed forms. The structure of YgjK adopted the closed form when subsite -1 was occupied by glucose. These results suggest that sugars containing the Glc12Gal structure are the most likely candidates for natural substrates of YgjK.

PubMed: 23826932
DOI: 10.1111/febs.12424

実験手法

X-RAY DIFFRACTION (2 Å)