Download MendeleySubstrate-induced closure of the flap domain in the ternary complex structures provides insights into the mechanism of catalysis by 3-hydroxy-3-methylglutaryl-CoA reductase.
Tabernero, L., Bochar, D.A., Rodwell, V.W., Stauffacher, C.V.(1999) Proc Natl Acad Sci U S A 96: 7167-7171
- PubMed: 10377386
- DOI: https://doi.org/10.1073/pnas.96.13.7167
- Primary Citation of Related Structures:
1QAX, 1QAY - PubMed Abstract:
3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase is the rate-limiting enzyme and the first committed step in the biosynthesis of cholesterol in mammals. We have determined the crystal structures of two nonproductive ternary complexes of HMG-CoA reductase, HMG-CoA/NAD+ and mevalonate/NADH, at 2.8 A resolution. In the structure of the Pseudomonas mevalonii apoenzyme, the last 50 residues of the C terminus (the flap domain), including the catalytic residue His381, were not visible. The structures of the ternary complexes reported here reveal a substrate-induced closing of the flap domain that completes the active site and aligns the catalytic histidine proximal to the thioester of HMG-CoA. The structures also present evidence that Lys267 is critically involved in catalysis and provide insights into the catalytic mechanism.
Organizational Affiliation:
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
