1E1F

Crystal structure of a Monocot (Maize ZMGlu1) beta-glucosidase in complex with p-Nitrophenyl-beta-D-thioglucoside

1E1F の概要

• エントリーDOI: 10.2210/pdb1e1f/pdb
• 関連するPDBエントリー: 1CBG 1E1E 1E4L 1E4N
• 分子名称: BETA-GLUCOSIDASE, 4-nitrophenyl 1-thio-beta-D-glucopyranoside (3 entities in total)
• 機能のキーワード: hydrolase, glycoside hydrolase, beta-glucosidase, family 1, retention of the anomeric configuration, pnp-beta-d-thioglucoside
• 由来する生物種: ZEA MAYS (MAIZE)
• 細胞内の位置: Plastid, chloroplast: P49235
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 117579.52

構造登録者

Czjzek, M.,Cicek, M.,Bevan, D.R.,Henrissat, B.,Esen, A. (登録日: 2000-05-03, 公開日: 2001-02-19, 最終更新日: 2023-12-06)

主引用文献

Czjzek, M.,Cicek, M.,Zamboni, V.,Burmeister, W.P.,Bevan, D.R.,Henrissat, B.,Esen, A.
Crystal Structure of a Monocotyledon (Maize Zmglu1) Beta-Glucosidase and a Model of its Complex with P-Nitrophenyl Beta-D-Thioglucoside
Biochem.J., 354:37-, 2001

PubMed Abstract: The maize beta-glucosidase isoenzymes ZMGlu1 and ZMGlu2 hydrolyse the abundant natural substrate DIMBOAGlc (2-O-beta-D-glucopyranosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one), whose aglycone DIMBOA (2,4-hydroxy-7-methoxy-1,4-benzoxazin-3-one) is the major defence chemical protecting seedlings and young plant parts against herbivores and other pests. The two isoenzymes hydrolyse DIMBOAGlc with similar kinetics but differ from each other and their sorghum homologues with respect to specificity towards other substrates. To gain insights into the mechanism of substrate (i.e. aglycone) specificity between the two maize isoenzymes and their sorghum homologues, ZMGlu1 was produced in Escherichia coli, purified, crystallized and its structure solved at 2.5 Angstrom resolution by X-ray crystallography. In addition, the complex of ZMGlu1 with the non-hydrolysable inhibitor p-nitrophenyl beta-D-thioglucoside was crystallized and, based on the partial electron density, a model for the inhibitor molecule within the active site is proposed. The inhibitor is located in a slot-like active site where its aromatic aglycone is held by stacking interactions with Trp-378. Whereas some of the atoms on the non-reducing end of the glucose moiety can be modelled on the basis of the electron density, most of the inhibitor atoms are highly disordered. This is attributed to the requirement of the enzyme to accommodate two different species, namely the substrate in its ground state and in its distorted conformation, for catalysis.

PubMed: 11171077
DOI: 10.1042/0264-6021:3540037

実験手法

X-RAY DIFFRACTION (2.6 Å)