4I6Y: 3-hydroxy-3-methyl (HMG) Coenzyme A Reductase bound to R-Mevalonate

In this study, we take advantage of the ability of HMG-CoA reductase (HMGR) from Pseudomonas mevalonii to remain active while in its crystallized form to study the changing interactions between the ligands and protein as the first reaction intermediate is created. HMG-CoA reductase catalyzes one of the few double oxidation-reduction reactions in intermediary metabolism that take place in a single active site. Our laboratory has undertaken an exploration of this reaction space using structures of HMG-CoA reductase complexed with various substrate, nucleotide, product, and inhibitor combinations. With a focus in this publication on the first hydride transfer, our structures follow this reduction reaction as the enzyme converts the HMG-CoA thioester from a flat sp(2)-like geometry to a pyramidal thiohemiacetal configuration consistent with a transition to an sp(3) orbital. This change in the geometry propagates through the coenzyme A (CoA) ligand whose first amide bond is rotated 180 degrees where it anchors a web of hydrogen bonds that weave together the nucleotide, the reaction intermediate, the enzyme, and the catalytic residues. This creates a stable intermediate structure prepared for nucleotide exchange and the second reduction reaction within the HMG-CoA reductase active site. Identification of this reaction intermediate provides a template for the development of an inhibitor that would act as an antibiotic effective against the HMG-CoA reductase of methicillin-resistant Staphylococcus aureus.
PDB ID: 4I6YDownload
MMDB ID: 111838
PDB Deposition Date: 2012/11/30
Updated in MMDB: 2013/12
Experimental Method:
x-ray diffraction
Resolution: 1.45  Å
Source Organism:
Similar Structures:
Biological Unit for 4I6Y: dimeric; determined by author and by software (PISA)
Molecular Components in 4I6Y
Label Count Molecule
Proteins (2 molecules)
3-hydroxy-3-methylglutaryl-coenzyme a Reductase
Molecule annotation
Chemicals (13 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB