MetaCyc Enzyme: hydroxymethylglutaryl-CoA lyase

Gene: mvaB Accession Number: G-9191 (MetaCyc)

Species: Pseudomonas mevalonii

Subunit composition of hydroxymethylglutaryl-CoA lyase = [MvaB]2
         hydroxymethylglutaryl-CoA lyase monomer = MvaB

The activity of hydroxymethylglutaryl-CoA lyase monomer has been initially documented in 1955 by Bachhawat et al from mammalian tissues, including pig heart, liver and kidney, and pigeon liver. They partially purified the enzyme from pig heart [Bachhawat55]. In 1967 the activity was first demonstrated in bacteria by Siddiqi and Rodwell, who isolated a (R)-mevalonate degrading bacterium from soil [Siddiqi67]. The organism, known only as Actinomycete S4, was capable of growth using (R)-mevalonate as the sole carbon source, converting it to acetoacetate and acetyl-CoA. Siddiqi and Rodwell were able to show that (S)-3-hydroxy-3-methylglutaryl-CoA was the intermediate in the process.

The enzyme was purified 650-fold from cell extracts, to a specific activity of 22 μmol acetyl-CoA formed per min per mg protei. The purified enzyme, which was monomeric, required either Mn2+ or Mg2+ for activityn [Scher89].

The gene encoding the enzyme was discovered in 1989 by Anderson and Rodwell, who were working with a different (R)-mevalonate degrading bacterium, Pseudomonas mevalonii [Anderson89b]. The gene, which resides in an operon with the gene encoding hydroxymethylglutaryl-CoA reductase, was cloned and overexpressed in Escherichia coli.

In a subsequent study, atomic absorption and EPR analyses of isolated enzyme indicated the presence of tightly bound copper. Copper-enriched enzyme displayed enhanced thermal stability [Narasimhan92]. Study of the copper binding site by multifrequency electron spin resonance spectroscopy suggested that at least two (and probably only two) nitrogen donor atoms are liganded to the tightly bound copper, and that the enzyme is composed of two identical subunits [Narasimhan94].

Affinity labeling of the enzyme suggested that cysteine-237 forms the active site [Hruz92]. This result was later confirmed by site-directed mutagenesis [Narasimhan95].

Gene Citations: [Beach89]

Locations: cytosol

Molecular Weight of Polypeptide: 31.609 kD (from nucleotide sequence), 31.6 kD (experimental) [Anderson89b ]

Unification Links: ModBase:P13703 , Protein Model Portal:P13703 , SMR:P13703 , Swiss-Model:P13703 , UniProt:P13703

Relationship Links: Entrez-Nucleotide:PART-OF:M24016 , InterPro:IN-FAMILY:IPR000138 , InterPro:IN-FAMILY:IPR000891 , InterPro:IN-FAMILY:IPR013785 , InterPro:IN-FAMILY:IPR027167 , Panther:IN-FAMILY:PTHR10277:SF1 , Pfam:IN-FAMILY:PF00682 , Prosite:IN-FAMILY:PS01062 , Prosite:IN-FAMILY:PS50991

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Cellular Component: GO:0005829 - cytosol [Anderson89b]

Created 12-Jan-2012 by Caspi R , SRI International

Enzymatic reaction of: hydroxymethylglutaryl-CoA lyase

EC Number:

(S)-3-hydroxy-3-methylglutaryl-CoA <=> acetoacetate + acetyl-CoA

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: L-leucine degradation I , mevalonate degradation

Cofactors or Prosthetic Groups: Mg2+ [Narasimhan92], Cu2+ [Narasimhan92], Mn2+ [Scher89]

Inhibitors (Other): o-phenanthroline [Narasimhan92]

Kinetic Parameters:

Km (μM)
Specific Activity (U/mg)

pH(opt): 8.8 [Scher89]


Anderson89b: Anderson DH, Rodwell VW (1989). "Nucleotide sequence and expression in Escherichia coli of the 3-hydroxy-3-methylglutaryl coenzyme A lyase gene of Pseudomonas mevalonii." J Bacteriol 171(12);6468-72. PMID: 2687236

Bachhawat55: Bachhawat, B.K., Robinson, W.G., Coon, M.J. (1955). "The enzymatic cleavage of beta-hydroxy-beta-methylglutaryl coenzyme A to acetoacetate and acetyl coenzyme A." J Biol Chem 216(2);727-36. PMID: 13271348

Beach89: Beach MJ, Rodwell VW (1989). "Cloning, sequencing, and overexpression of mvaA, which encodes Pseudomonas mevalonii 3-hydroxy-3-methylglutaryl coenzyme A reductase." J Bacteriol 171(6);2994-3001. PMID: 2656635

Hruz92: Hruz PW, Narasimhan C, Miziorko HM (1992). "3-Hydroxy-3-methylglutaryl coenzyme A lyase: affinity labeling of the Pseudomonas mevalonii enzyme and assignment of cysteine-237 to the active site." Biochemistry 31(29);6842-7. PMID: 1637819

Narasimhan92: Narasimhan C, Miziorko HM (1992). "Pseudomonas mevalonii 3-hydroxy-3-methylglutaryl-CoA lyase: characterization of the isolated recombinant protein and investigation of the enzyme's cation requirements." Biochemistry 31(45);11224-30. PMID: 1332752

Narasimhan94: Narasimhan C, Antholine WE, Miziorko HM (1994). "P. mevalonii 3-hydroxy-3-methylglutaryl-CoA lyase: electron paramagnetic resonance investigation of the copper binding site." Arch Biochem Biophys 312(2);467-73. PMID: 7913596

Narasimhan95: Narasimhan C, Roberts JR, Miziorko HM (1995). "Pseudomonas mevalonii 3-hydroxy-3-methylglutaryl-CoA lyase: testing the function of the active site cysteine by site-directed mutagenesis." Biochemistry 34(31);9930-5. PMID: 7632692

Scher89: Scher DS, Rodwell VW (1989). "3-Hydroxy-3-methylglutaryl coenzyme A lyase from Pseudomonas mevalonii." Biochim Biophys Acta 1003(3);321-6. PMID: 2742863

Siddiqi67: Siddiqi MA, Rodwell VW (1967). "Bacterial metabolism of mevalonic acid." J Bacteriol 93(1);207-14. PMID: 4289807

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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