2V7B

Crystal structures of a benzoate CoA ligase from Burkholderia xenovorans LB400

2V7B の概要

• エントリーDOI: 10.2210/pdb2v7b/pdb
• 分子名称: BENZOATE-COENZYME A LIGASE, BENZOIC ACID (3 entities in total)
• 機能のキーワード: ligase, benzoate oxidation, benzoate coa ligase
• 由来する生物種: BURKHOLDERIA XENOVORANS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 115143.05

構造登録者

J Boulanger, M.,Bains, J. (登録日: 2007-07-27, 公開日: 2007-10-02, 最終更新日: 2023-12-13)

主引用文献

Bains, J.,Boulanger, M.J.
Biochemical and Structural Characterization of the Paralogous Benzoate Coa Ligases from Burkholderia Xenovorans Lb400: Defining the Entry Point Into the Novel Benzoate Oxidation (Box) Pathway.
J.Mol.Biol., 373:965-, 2007

PubMed Abstract: Xenobiotic aromatic compounds represent one of the most significant classes of environmental pollutants. A novel benzoate oxidation (box) pathway has been identified recently in Burkholderia xenovorans LB400 (referred to simply as LB400) that is capable of assimilating benzoate and intimately tied to the degradation of polychlorinated biphenyls (PCBs). The box pathway in LB400 is present in two paralogous copies (boxM and boxC) and encodes eight enzymes with the first committed step catalyzed by benzoate CoA ligase (BCL). As a first step towards delineating the biochemical role of the box pathway in LB400, we have carried out functional studies of the paralogous BCL enzymes (BCLM and BCLC) with 20 different putative substrates. We have established a structural rationale for the observed substrate specificities on the basis of a 1.84 A crystal structure of BCLM in complex with benzoate. These data show that, while BCLM and BCLC display similar overall substrate specificities, BCLM is significantly more active towards benzoate and 2-aminobenzoate with tighter binding (Km) and a faster reaction rate (Vmax). Despite these clear functional differences, the residues that define the substrate-binding site in BCLM are completely conserved in BCLC, suggesting that second shell residues may play a significant role in substrate recognition and catalysis. Furthermore, comparison of the active site of BCLM with the recently solved structures of 4-chlorobenzoate CoA ligase and 2, 3-dihydroxybenzoate CoA ligase offers additional insight into the molecular features that mediate substrate binding in adenylate-forming enzymes. This study provides the first biochemical characterization of a Box enzyme from LB400 and the first structural characterization of a Box enzyme from any organism, and further substantiates the concept of distinct roles for the two paralogous box pathways in LB400.

PubMed: 17884091
DOI: 10.1016/J.JMB.2007.08.008

実験手法

X-RAY DIFFRACTION (1.84 Å)