1JDB

CARBAMOYL PHOSPHATE SYNTHETASE FROM ESCHERICHIA COLI

1JDB の概要

• エントリーDOI: 10.2210/pdb1jdb/pdb
• 分子名称: CARBAMOYL PHOSPHATE SYNTHETASE, TETRAETHYLAMMONIUM ION, MANGANESE (II) ION, ... (11 entities in total)
• 機能のキーワード: ligase, amidotransferase, synthase
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 647382.71

構造登録者

Thoden, J.B.,Holden, H.M.,Wesenberg, G.,Raushel, F.M.,Rayment, I. (登録日: 1997-03-25, 公開日: 1998-06-17, 最終更新日: 2024-04-03)

主引用文献

Thoden, J.B.,Raushel, F.M.,Benning, M.M.,Rayment, I.,Holden, H.M.
The structure of carbamoyl phosphate synthetase determined to 2.1 A resolution.
Acta Crystallogr.,Sect.D, 55:8-24, 1999

PubMed Abstract: Carbamoyl phosphate synthetase catalyzes the formation of carbamoyl phosphate from one molecule of bicarbonate, two molecules of Mg2+ATP and one molecule of glutamine or ammonia depending upon the particular form of the enzyme under investigation. As isolated from Escherichia coli, the enzyme is an alpha,beta-heterodimer consisting of a small subunit that hydrolyzes glutamine and a large subunit that catalyzes the two required phosphorylation events. Here the three-dimensional structure of carbamoyl phosphate synthetase from E. coli refined to 2.1 A resolution with an R factor of 17.9% is described. The small subunit is distinctly bilobal with a catalytic triad (Cys269, His353 and Glu355) situated between the two structural domains. As observed in those enzymes belonging to the alpha/beta-hydrolase family, the active-site nucleophile, Cys269, is perched at the top of a tight turn. The large subunit consists of four structural units: the carboxyphosphate synthetic component, the oligomerization domain, the carbamoyl phosphate synthetic component and the allosteric domain. Both the carboxyphosphate and carbamoyl phosphate synthetic components bind Mn2+ADP. In the carboxyphosphate synthetic component, the two observed Mn2+ ions are both octahedrally coordinated by oxygen-containing ligands and are bridged by the carboxylate side chain of Glu299. Glu215 plays a key allosteric role by coordinating to the physiologically important potassium ion and hydrogen bonding to the ribose hydroxyl groups of ADP. In the carbamoyl phosphate synthetic component, the single observed Mn2+ ion is also octahedrally coordinated by oxygen-containing ligands and Glu761 plays a similar role to that of Glu215. The carboxyphosphate and carbamoyl phosphate synthetic components, while topologically equivalent, are structurally different, as would be expected in light of their separate biochemical functions.

PubMed: 10089390
DOI: 10.1107/S0907444998006234

実験手法

X-RAY DIFFRACTION (2.1 Å)