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Trans-Isoprenyl Diphosphate Synthases. Trans-Isoprenyl Diphosphate Synthases (Trans_IPPS) of class 1 isoprenoid biosynthesis enzymes which either synthesis geranyl/farnesyl diphosphates (GPP/FPP) or longer chained products from isoprene precursors, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), or use geranyl (C10)-, farnesyl (C15)-, or geranylgeranyl (C20)-diphosphate as substrate. These enzymes produce a myriad of precursors for such end products as steroids, cholesterol, sesquiterpenes, heme, carotenoids, retinoids, diterpenes, ubiquinone, and archaeal ether linked lipids; and are widely distributed among archaea, bacteria, and eukareya. The enzymes in this family share the same 'isoprenoid synthase fold' and include the head-to-tail (HT) IPPS which catalyze the successive 1'-4 condensation of the 5-carbon IPP to the growing isoprene chain to form linear, all-trans, C10-, C15-, C20- C25-, C30-, C35-, C40-, C45-, or C50-isoprenoid diphosphates. The head-to-head (HH) IPPS catalyze the successive 1'-1 condensation of 2 farnesyl or 2 geranylgeranyl isoprenoid diphosphates. Isoprenoid chain elongation reactions proceed via electrophilic alkylations in which a new carbon-carbon single bond is generated through interaction between a highly reactive electron-deficient allylic carbocation and an electron-rich carbon-carbon double bond. The catalytic site consists of a large central cavity formed by mostly antiparallel alpha helices with two aspartate-rich regions located on opposite walls. These residues mediate binding of prenyl phosphates via bridging Mg2+ ions, inducing proposed conformational changes that close the active site to solvent, stabilizing reactive carbocation intermediates. Mechanistically and structurally distinct, cis-IPPS are not included in this CD.
No pairwise interactions are available for this conserved domain.
Tips:  If you've navigated here from a protein, hovering over a position on the weblogo will display the corresponding protein position for that domain position. The histograms below the weblogo indicate mutations found on the domain. Red is for disease (OMIM) and blue is for SNPs. Functional Features are displayed as orange boxes under the histograms. You can choose which features are displayed in the box below. Range on the Protein: Protein ID Protein Position Domain Position: 
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