2FAF

The structure of chicken mitochondrial PEPCK.

2FAF の概要

• エントリーDOI: 10.2210/pdb2faf/pdb
• 関連するBIRD辞書のPRD_ID: PRD_900043
• 分子名称: Phosphoenolpyruvate carboxykinase, beta-D-fructofuranose-(2-1)-6-O-octanoyl-alpha-D-glucopyranose, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (6 entities in total)
• 機能のキーワード: phosphoenolpyruvate carboxykinase, pepck, kinase, phosphoryl transfer, lyase
• 由来する生物種: Gallus gallus (chicken)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 135838.72

構造登録者

Holyoak, T.,Sullivan, S.M.,Nowak, T. (登録日: 2005-12-07, 公開日: 2006-06-27, 最終更新日: 2023-08-30)

主引用文献

Holyoak, T.,Sullivan, S.M.,Nowak, T.
Structural Insights into the Mechanism of PEPCK Catalysis
Biochemistry, 45:8254-8263, 2006

PubMed Abstract: Phosphoenolpyruvate carboxykinase catalyzes the reversible decarboxylation of oxaloacetic acid with the concomitant transfer of the gamma-phosphate of GTP to form PEP and GDP as the first committed step of gluconeogenesis and glyceroneogenesis. The three structures of the mitochondrial isoform of PEPCK reported are complexed with Mn2+, Mn2+-PEP, or Mn2+-malonate-Mn2+ GDP and provide the first observations of the structure of the mitochondrial isoform and insight into the mechanism of catalysis mediated by this enzyme. The structures show the involvement of the hyper-reactive cysteine (C307) in the coordination of the active site Mn2+. Upon formation of the PEPCK-Mn2+-PEP or PEPCK-Mn2+-malonate-Mn2+ GDP complexes, C307 coordination is lost as the P-loop in which it resides adopts a different conformation. The structures suggest that stabilization of the cysteine-coordinated metal geometry holds the enzyme as a catalytically incompetent metal complex and may represent a previously unappreciated mechanism of regulation. A third conformation of the mobile P-loop in the PEPCK-Mn2+-malonate-Mn2+ GDP complex demonstrates the participation of a previously unrecognized, conserved serine residue (S305) in mediating phosphoryl transfer. The ordering of the mobile active site lid in the PEPCK-Mn2+-malonate-Mn2+ GDP complex yields the first observation of this structural feature and provides additional insight into the mechanism of phosphoryl transfer.

PubMed: 16819824
DOI: 10.1021/bi060269g

実験手法

X-RAY DIFFRACTION (1.7 Å)