In a thiolase-mediated reaction, 2 molecules of acetyl-CoA condense to form acetoacetyl-CoA
, and subsequently 3-hydroxy, 3methylglutaryl-CoA (3-HMG-CoA).
phaR (PHB synthase subunit), phaB (acetoacetyl-coA reductase), and phaC (PHB synthase subunit) are divergently transcribed as a tricistronic operon; padR/phaQ (transcription regulator), phaP (Phasin protein), and phaJ are transcribed in one direction.
cereus tsu1 genome including several phaA genes and a gene cluster with six PHA genes: phaR (PHB synthase subunit),phaB (acetoacetyl-coA reductase), phaC (PHB synthase), and a phaJ, the downstream phaP (Phasin protein), and the padR (PhaQ transcription regulator) (see Table S7 in the Supplementary Material).
3-Hydroxy-3-methylglutaryl-Coenzyme A synthase(HMGS) is the second enzyme in MVA pathway of isoprenoid biosynthesis, and catalyzes the condensation of acetyl-CoA with acetoacetyl-CoA to yield HMG-CoA.A growing body of evidence now indicates that HMGS plays significant roles in biosynthesis of terpenoids in plants.
Biological significance of plant HMGS in the MVA pathway: As an important condensing enzyme in the MVA pathway, HMGS can catalyze condensation of acetyl-CoA and acetoacetyl-CoA to generate HMG-CoA, which is further converted into generate MVA by HMGR.
Novel acetoacetyl-CoA synthesizing enzyme found in the Streptomyces MVA pathway gene clusters
(35) The MVA pathway begins with the synthesis of acetoacetyl-CoA, which was first reported to be biosynthesized via a thioester-dependent Claisen condensation reaction between two molecules of acetyl-CoA, and is catalyzed by acetoacetyl-CoA thiolase (EC 22.214.171.124).
FabG assay was performed at 25 [degrees] C in 20 mM Hepes pH 7.0 in the presence of 1 [micro]g (36 nM) enzyme, 100 [micro]M NADPH, 35 mM NaCl and 1% DMSO by following for 1 min the oxidation of NADPH to [NADP.sup.+] at 340 nm using 50 [micro]M acetoacetyl-CoA
Acetyl-Coenzyme A acetyltransferase 2 (ACAT) transforms acetyl-CoA into acetoacetyl-CoA
and can increases the rate of ketogenesis.
Activities of 3-hydroxybutyrate dehydrogenase, 3-oxoacid CoA-transferase and acetoacetyl-CoA
thiolase in relation to ketone-body utilisation in muscles from vertebrates and invertebrates.
Increased lipolysis results in the overproduction of acetoacetyl-CoA
, which then acts as the substrate for hepatic formation of ketone bodies.
Louis, MO) and [C.sub.4] (acetoacetyl-CoA
; Laroden Fine Chemicals, Malmo, Sweden) substrate in liver supernate did not decline for at least 4 h under these conditions.