4YBO

Structure of Citrate Synthase from the Thermoacidophilic Euryarchaeon Thermolasma acidophilum

4YBO の概要

• エントリーDOI: 10.2210/pdb4ybo/pdb
• 関連するPDBエントリー: 2ifc 2r26 2r9e
• 分子名称: Citrate synthase, BICARBONATE ION (3 entities in total)
• 機能のキーワード: tricarboxylic acid cycle, transferase, carbohydrate metabolism
• 由来する生物種: Thermoplasma acidophilum (strain ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 179070.05

構造登録者

Murphy, J.R.,Donini, S.,Kappock, T.J. (登録日: 2015-02-19, 公開日: 2015-09-02, 最終更新日: 2023-09-27)

主引用文献

Murphy, J.R.,Donini, S.,Kappock, T.J.
An active site-tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase.
Acta Crystallogr F Struct Biol Commun, 71:1292-1299, 2015

PubMed Abstract: Citrate synthase (CS) plays a central metabolic role in aerobes and many other organisms. The CS reaction comprises two half-reactions: a Claisen aldol condensation of acetyl-CoA (AcCoA) and oxaloacetate (OAA) that forms citryl-CoA (CitCoA), and CitCoA hydrolysis. Protein conformational changes that `close' the active site play an important role in the assembly of a catalytically competent condensation active site. CS from the thermoacidophile Thermoplasma acidophilum (TpCS) possesses an endogenous Trp fluorophore that can be used to monitor the condensation reaction. The 2.2 Å resolution crystal structure of TpCS fused to a C-terminal hexahistidine tag (TpCSH6) reported here is an `open' structure that, when compared with several liganded TpCS structures, helps to define a complete path for active-site closure. One active site in each dimer binds a neighboring His tag, the first nonsubstrate ligand known to occupy both the AcCoA and OAA binding sites. Solution data collectively suggest that this fortuitous interaction is stabilized by the crystalline lattice. As a polar but almost neutral ligand, the active site-tail interaction provides a new starting point for the design of bisubstrate-analog inhibitors of CS.

PubMed: 26457521
DOI: 10.1107/S2053230X15015939

実験手法

X-RAY DIFFRACTION (2.179 Å)