2SFP

ALANINE RACEMASE WITH BOUND PROPIONATE INHIBITOR

2SFP の概要

• エントリーDOI: 10.2210/pdb2sfp/pdb
• 分子名称: PROTEIN (ALANINE RACEMASE), PYRIDOXAL-5'-PHOSPHATE, PROPANOIC ACID, ... (4 entities in total)
• 機能のキーワード: racemase, isomerase, alanine, pyridoxal phosphate
• 由来する生物種: Geobacillus stearothermophilus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 88032.58

構造登録者

Morollo, A.A.,Petsko, G.A.,Ringe, D. (登録日: 1999-02-16, 公開日: 1999-02-24, 最終更新日: 2023-11-15)

主引用文献

Morollo, A.A.,Petsko, G.A.,Ringe, D.
Structure of a Michaelis complex analogue: propionate binds in the substrate carboxylate site of alanine racemase.
Biochemistry, 38:3293-3301, 1999

PubMed Abstract: The structure of alanine racemase from Bacillus stearothermophilus with the inhibitor propionate bound in the active site was determined by X-ray crystallography to a resolution of 1.9 A. The enzyme is a homodimer in solution and crystallizes with a dimer in the asymmetric unit. Both active sites contain a pyridoxal 5'-phosphate (PLP) molecule in aldimine linkage to Lys39 as a protonated Schiff base, and the pH-independence of UV-visible absorption spectra suggests that the protonated PLP-Lys39 Schiff base is the reactive form of the enzyme. The carboxylate group of propionate bound in the active site makes numerous interactions with active-site residues, defining the substrate binding site of the enzyme. The propionate-bound structure therefore approximates features of the Michaelis complex formed between alanine racemase and its amino acid substrate. The structure also provides evidence for the existence of a carbamate formed on the side-chain amino group of Lys129, stabilized by interactions with one of the residues interacting with the carboxylate group of propionate, Arg136. We propose that this novel interaction influences both substrate binding and catalysis by precisely positioning Arg136 and modulating its charge.

PubMed: 10079072
DOI: 10.1021/bi9822729

実験手法

X-RAY DIFFRACTION (1.9 Å)