1x9e
From Proteopedia
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Crystal structure of HMG-CoA synthase from Enterococcus faecalis
Overview
Biosynthesis of the isoprenoid precursor, isopentenyl diphosphate, is a critical function in all independently living organisms. There are two major pathways for this synthesis, the non-mevalonate pathway found in most eubacteria and the mevalonate pathway found in animal cells and a number of pathogenic bacteria. An early step in this pathway is the condensation of acetyl-CoA and acetoacetyl-CoA into HMG-CoA, catalyzed by the enzyme HMG-CoA synthase. To explore the possibility of a small molecule inhibitor of the enzyme functioning as a non-cell wall antibiotic, the structure of HMG-CoA synthase from Enterococcus faecalis (MVAS) was determined by selenomethionine MAD phasing to 2.4 A and the enzyme complexed with its second substrate, acetoacetyl-CoA, to 1.9 A. These structures show that HMG-CoA synthase from Enterococcus is a member of the family of thiolase fold enzymes and, while similar to the recently published HMG-CoA synthase structures from Staphylococcus aureus, exhibit significant differences in the structure of the C-terminal domain. The acetoacetyl-CoA binary structure demonstrates reduced coenzyme A and acetoacetate covalently bound to the active site cysteine through a thioester bond. This is consistent with the kinetics of the reaction that have shown acetoacetyl-CoA to be a potent inhibitor of the overall reaction, and provides a starting point in the search for a small molecule inhibitor.
About this Structure
1X9E is a Single protein structure of sequence from Enterococcus faecalis with as ligand. Active as Hydroxymethylglutaryl-CoA synthase, with EC number 2.3.3.10 Full crystallographic information is available from OCA.
Reference
X-ray crystal structures of HMG-CoA synthase from Enterococcus faecalis and a complex with its second substrate/inhibitor acetoacetyl-CoA., Steussy CN, Vartia AA, Burgner JW 2nd, Sutherlin A, Rodwell VW, Stauffacher CV, Biochemistry. 2005 Nov 1;44(43):14256-67. PMID:16245942
Page seeded by OCA on Thu Feb 21 15:52:23 2008
