InterPro domain: IPR005914

Isoprenoids are a large class of compounds, with more than 20,000 structures currently known, which are found in all living organisms. Some play essential physiological roles, such as sterols that stabilise cell membranes or carotenoids involved in photosynthesis, while the function of many others is not well understood. In all eukaryotes and some prokaryotes, isoprenoids are synthesised by the mevalonate pathway, while most prokaryotes use a mevalonate-independent pathway [ 1 , 2 ].

This entry represents acetoacetyl-CoA synthase ( 6.2.1.16 ), catalysing the first step of the mevalonate pathway of isoprenoid biosynthesis via isopentenyl diphosphate. ATP + acetoacetate + CoA = AMP + diphosphate + acetoacetyl-CoA

A Sinorhizobium protein in this entry is also required for growth on polyhydroxybutyrate, a commonly used carbon storage molecule in bacteria [ 3 ]. This entry also includes malonamoyl-CoA synthetase which in Penicillium is involved in the biosynthesis of the tetracycline-like viridicatumtoxin [ 4 ].

1. Production of mevalonate by a metabolically-engineered Escherichia coli. Biotechnol. Lett. 26, 1487-91
2. Isoprenoid biosynthesis in bacteria: a novel pathway for the early steps leading to isopentenyl diphosphate. Biochem. J. 295 ( Pt 2), 517-24
3. Requirement for the enzymes acetoacetyl coenzyme A synthetase and poly-3-hydroxybutyrate (PHB) synthase for growth of Sinorhizobium meliloti on PHB cycle intermediates. J. Bacteriol. 182, 2113-8
4. Identification of the viridicatumtoxin and griseofulvin gene clusters from Penicillium aethiopicum. Chem. Biol. 17, 483-94