1CHM

ENZYMATIC MECHANISM OF CREATINE AMIDINOHYDROLASE AS DEDUCED FROM CRYSTAL STRUCTURES

1CHM の概要

• エントリーDOI: 10.2210/pdb1chm/pdb
• 分子名称: CREATINE AMIDINOHYDROLASE, CARBAMOYL SARCOSINE (3 entities in total)
• 機能のキーワード: creatinase
• 由来する生物種: Pseudomonas putida
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 90930.49

構造登録者

Hoeffken, H.W.,Knof, S.H.,Bartlett, P.A.,Huber, R.,Moellering, H.,Schumacher, G. (登録日: 1993-07-19, 公開日: 1994-04-30, 最終更新日: 2024-02-07)

主引用文献

Coll, M.,Knof, S.H.,Ohga, Y.,Messerschmidt, A.,Huber, R.,Moellering, H.,Russmann, L.,Schumacher, G.
Enzymatic mechanism of creatine amidinohydrolase as deduced from crystal structures.
J.Mol.Biol., 214:597-610, 1990

PubMed Abstract: Crystal structures of the enzyme creatine amidinohydrolase (creatinase, EC 3.5.3.3) with two different inhibitors, the reaction product sarcosine and the substrate creatine, bound have been analyzed by X-ray diffraction methods. With the inhibitor carbamoyl sarcosine, two different crystal forms at different pH values have been determined. An enzymatic mechanism is proposed on the basis of the eight structures analyzed. The enzyme binds substrate and inhibitor in a distorted geometry where the urea resonance is broken. His232 is the general base and acid, and acts as a proton shuttle. It withdraws a proton from water 377 and donates it to the N(3) atom of the guanidinium group. OH- 377 adds to the C(1) atom of the guanidinium group to form a urea hydrate. Proton withdrawal by His232 leads to products. The reaction product sarcosine binds to the active site in a reverse orientation. The free enzyme was found to have a bicarbonate bound to the active site.

PubMed: 1696320
DOI: 10.1016/0022-2836(90)90201-V

実験手法

X-RAY DIFFRACTION (1.9 Å)