Publication Date:
1995-06-23
Description:
The rate-limiting step in cholesterol biosynthesis in mammals is catalyzed by 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, a four-electron oxidoreductase that converts HMG-CoA to mevalonate. The crystal structure of HMG-CoA reductase from Pseudomonas mevalonii was determined at 3.0 angstrom resolution by multiple isomorphous replacement. The structure reveals a tightly bound dimer that brings together at the subunit interface the conserved residues implicated in substrate binding and catalysis. These dimers are packed about a threefold crystallographic axis, forming a hexamer with 23 point group symmetry. Difference Fourier studies reveal the binding sites for the substrates HMG-CoA and reduced or oxidized nicotinamide adenine dinucleotide [NAD(H)] and demonstrate that the active sites are at the dimer interfaces. The HMG-CoA is bound by a domain with an unusual fold, consisting of a central alpha helix surrounded by a triangular set of walls of beta sheets and alpha helices. The NAD(H) is bound by a domain characterized by an antiparallel beta structure that defines a class of dinucleotide-binding domains.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lawrence, C M -- Rodwell, V W -- Stauffacher, C V -- AI 127713/AI/NIAID NIH HHS/ -- HL 47113/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1995 Jun 23;268(5218):1758-62.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7792601" target="_blank"〉PubMed〈/a〉
Keywords:
Acyl Coenzyme A/metabolism
;
Amino Acid Sequence
;
Binding Sites
;
Computer Graphics
;
Crystallography, X-Ray
;
Fourier Analysis
;
Hydroxymethylglutaryl CoA Reductases/*chemistry/metabolism
;
Models, Molecular
;
Molecular Sequence Data
;
NAD/metabolism
;
Protein Folding
;
Protein Structure, Secondary
;
Pseudomonas/*enzymology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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