9RUB

CRYSTAL STRUCTURE OF ACTIVATED RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE COMPLEXED WITH ITS SUBSTRATE, RIBULOSE-1,5-BISPHOSPHATE

9RUB の概要

• エントリーDOI: 10.2210/pdb9rub/pdb
• 分子名称: RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE, RIBULOSE-1,5-DIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: lyase(carbon-carbon)
• 由来する生物種: Rhodospirillum rubrum
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 101838.68

構造登録者

Lundqvist, T.,Schneider, G. (登録日: 1990-11-28, 公開日: 1993-01-15, 最終更新日: 2025-03-26)

主引用文献

Lundqvist, T.,Schneider, G.
Crystal structure of activated ribulose-1,5-bisphosphate carboxylase complexed with its substrate, ribulose-1,5-bisphosphate.
J.Biol.Chem., 266:12604-12611, 1991

PubMed Abstract: The three-dimensional structure of the complex of ribulose-1,5-bisphosphate carboxylase from Rhodospirillum rubrum, CO2, Mg2+, and ribulose bisphosphate has been determined with x-ray crystallographic methods to 2.6-A resolution. Ribulose-1,5-bisphosphate binds across the active site with the two phosphate groups in the two phosphate binding sites of the beta/alpha barrel. The oxygen atoms of the carbamate and the side chain of Asp-193 provide the protein ligands to the bound Mg2+ ion. The C2 and the C3 or C4 oxygen atoms of the substrate are also within the first coordination sphere of the metal ion. At the present resolution of the electron density maps, two slightly different conformations of the substrate, with the C3 hydroxyl group "cis" or "trans" to the C2 oxygen, can be built into the observed electron density. The two different conformations suggest two different mechanisms of proton abstraction in the first step of catalysis, the enolization of the ribulose 1,5-bisphosphate. Two loop regions, which are disordered in the crystals of the nonactivated enzyme, could be built into their respective electron density. A comparison with the structure of the quaternary complex of the spinach enzyme shows that despite the different conformations of loop 6, the positions of the Mg2+ ion, and most atoms of the substrate are very similar when superimposed on each other. There are, however, some significant differences at the active site, especially in the metal coordination sphere.

PubMed: 1905726

実験手法

X-RAY DIFFRACTION (2.6 Å)