6CTS
PROPOSED MECHANISM FOR THE CONDENSATION REACTION OF CITRATE SYNTHASE. 1.9-ANGSTROMS STRUCTURE OF THE TERNARY COMPLEX WITH OXALOACETATE AND CARBOXYMETHYL COENZYME A
Summary for 6CTS
| Entry DOI | 10.2210/pdb6cts/pdb |
| Descriptor | CITRATE SYNTHASE, CITRYL-THIOETHER-COENZYME *A (3 entities in total) |
| Functional Keywords | oxo-acid-lyase |
| Biological source | Gallus gallus (chicken) |
| Cellular location | Mitochondrion matrix: P23007 |
| Total number of polymer chains | 1 |
| Total formula weight | 48249.83 |
| Authors | Karpusas, M.,Branchaud, B.,Remington, S.J. (deposition date: 1989-11-16, release date: 1990-10-15, Last modification date: 2024-03-13) |
| Primary citation | Karpusas, M.,Branchaud, B.,Remington, S.J. Proposed mechanism for the condensation reaction of citrate synthase: 1.9-A structure of the ternary complex with oxaloacetate and carboxymethyl coenzyme A. Biochemistry, 29:2213-2219, 1990 Cited by PubMed Abstract: The crystal structure of the ternary complex citrate synthase-oxaloacetate-carboxymethyl coenzyme A has been solved to a resolution of 1.9 A and refined to a conventional crystallographic R factor of 0.185. The structure resembles a proposed transition state of the condensation reaction and suggests that the condensation reaction proceeds through a neutral enol rather than an enolate intermediate. A mechanism for the condensation reaction is proposed which involves the participation of three key catalytic groups (Asp 375, His 274, and His 320) in two distinct steps. The proposed mechanism invokes concerted general acid-base catalysis twice to explain both the energetics of the reaction and the experimentally observed inversion of stereochemistry at the attacking carbon atom. PubMed: 2337600DOI: 10.1021/bi00461a002 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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