HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

3-Methylglutaconyl-CoA hydratase from Acinetobacter sp.

Abstract
Acinetobacter strain IVS-B aerobically grows on isovalerate as sole carbon and energy source. Isovalerate is metabolised via isovaleryl-CoA, an intermediate of the oxidative (S)-leucine degradation pathway. A 3-methylglutaconyl-CoA hydratase (EC 4.2.1.18) was purified 65-fold to apparent homogeneity from cell-free extracts of isovalerate-grown cells of Acinetobacter strain IVS-B. The enzyme was found to be a homotetramer (115.2 kDa) composed of four identical subunits of 28.8 kDa not containing any cofactors. The enzyme was shown to catalyse the hydration of (E)-glutaconyl-CoA (k (cat)=18 s(-1), K (m)=40 microM) and the dehydration of (S)-3-hydroxyglutaryl-CoA (k (cat)=13 s(-1), K (m)=52 microM), albeit with somewhat lower catalytic efficiencies as compared to the 3-methyl derivatives, 3-methylglutaconyl-CoA (k (cat)=138 s(-1), K (m)=14 microM) and (S)-3-hydroxy-3-methylglutaryl-CoA (k (cat)=60 s(-1), K (m)=36 microM). Thus, the mechanistically simple syn-addition of water to the (E)-isomer of 3-methylglutaconyl-CoA of the leucine degradative pathway leading to the common intermediate (S)-3-hydroxy-3-methylglutaryl-CoA was assigned as the major physiological role to this enzyme. The amino acid sequence of 3-methylglutaconyl-CoA hydratase from Acinetobacter sp. was found to be related to over 100 prokaryotic enoyl-CoA hydratases (up to 50% identity), possibly all being 3-methylglutaconyl-CoA hydratases.
AuthorsMatthias Mack, Michael Liesert, Johannes Zschocke, Verena Peters, Dietmar Linder, Wolfgang Buckel
JournalArchives of microbiology (Arch Microbiol) Vol. 185 Issue 4 Pg. 297-306 (May 2006) ISSN: 0302-8933 [Print] Germany
PMID16482430 (Publication Type: Journal Article)
Chemical References
  • Hydro-Lyases
  • methylglutaconyl-CoA hydratase
  • Leucine
Topics
  • Acinetobacter (classification, enzymology)
  • Amino Acid Sequence
  • Animals
  • Humans
  • Hydro-Lyases (chemistry, genetics, isolation & purification)
  • Kinetics
  • Leucine (metabolism)
  • Molecular Sequence Data
  • Sequence Alignment

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: