4O9C

Crystal structure of Beta-ketothiolase (PhaA) from Ralstonia eutropha H16

4O9C の概要

• エントリーDOI: 10.2210/pdb4o9c/pdb
• 関連するPDBエントリー: 4O99 4O9A
• 分子名称: Acetyl-CoA acetyltransferase, COENZYME A (3 entities in total)
• 機能のキーワード: phb biosynthesis, acyltransferase transferase, transferase
• 由来する生物種: Ralstonia eutropha
• 細胞内の位置: Cytoplasm: P14611
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 325389.57

構造登録者

Kim, E.J.,Kim, J.,Kim, S.,Kim, K.J. (登録日: 2014-01-02, 公開日: 2014-12-17, 最終更新日: 2024-03-20)

主引用文献

Kim, E.J.,Kim, K.J.
Crystal structure and biochemical characterization of PhaA from Ralstonia eutropha, a polyhydroxyalkanoate-producing bacterium.
Biochem.Biophys.Res.Commun., 452:124-129, 2014

PubMed Abstract: PhaA from Ralstonia eutropha (RePhaA) is the first enzyme in the polyhydroxyalbutyrate (PHB) biosynthetic pathway and catalyzes the condensation of two molecules of acetyl-CoA to acetoacetyl-CoA. To investigate the molecular mechanism underlying PHB biosynthesis, we determined the crystal structures of the RePhaA protein in apo- and CoA-bound forms. The RePhaA structure adopts the type II biosynthetic thiolase fold forming a tetramer by means of dimerization of two dimers. The crystal structure of RePhaA in complex with CoA revealed that the enzyme contained a unique Phe219 residue, resulting that the ADP moiety binds in somewhat different position compared with that bound in other thiolase enzymes. Our study provides structural insight into the substrate specificity of RePhaA. Results indicate the presence of a small pocket near the Cys88 covalent catalytic residue leading to the possibility of the enzyme to accommodate acetyl-CoA as a sole substrate instead of larger acyl-CoA molecules such as propionyl-CoA. Furthermore, the roles of key residues involved in substrate binding and enzyme catalysis were confirmed by site-directed mutagenesis.

PubMed: 25152395
DOI: 10.1016/j.bbrc.2014.08.074

実験手法

X-RAY DIFFRACTION (2 Å)