4YBO
Structure of Citrate Synthase from the Thermoacidophilic Euryarchaeon Thermolasma acidophilum
Summary for 4YBO
| Entry DOI | 10.2210/pdb4ybo/pdb |
| Related | 2ifc 2r26 2r9e |
| Descriptor | Citrate synthase, BICARBONATE ION (3 entities in total) |
| Functional Keywords | tricarboxylic acid cycle, transferase, carbohydrate metabolism |
| Biological source | Thermoplasma acidophilum (strain ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165) |
| Total number of polymer chains | 4 |
| Total formula weight | 179070.05 |
| Authors | Murphy, J.R.,Donini, S.,Kappock, T.J. (deposition date: 2015-02-19, release date: 2015-09-02, Last modification date: 2023-09-27) |
| Primary citation | 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 Cited by 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: 26457521DOI: 10.1107/S2053230X15015939 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.179 Å) |
Structure validation
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