Prenyltransferase
= Prenyltransferase
A <prenyltransferase> is an <enzyme> that transfers a <prenyl group>, an isoprenoid-derived carbon group, to an acceptor. The term covers multiple reactions; the acceptor can be a small <molecule> rather than a <protein>. It should therefore not be interpreted as meaning only an enzyme for protein <prenylation>.
One concrete reaction joins the five-carbon <dimethylallyl diphosphate> and five-carbon <isopentenyl diphosphate> to make ten-carbon <geranyl diphosphate>, releasing diphosphate. Carbon counting gives $5+5=10$, while the substrate names specify the activated donors and the product structure. The official entry for this enzyme also notes poor acceptance of larger prenyl diphosphates as donors: a generic transfer label does not imply unrestricted substrate choice.<Dimethylallyltranstransferase in IUBMB Enzyme Nomenclature>[EC 2.5.1.1, Reaction and Comments]{ref}
A different example links this chemistry to <Vitamin K>. In 2010, <Kimie Nakagawa> and colleagues identified <UBIAD1> as an enzyme for <menaquinone-4> biosynthesis. Reducing its expression suppressed conversion of deuterium-labelled vitamin-K derivatives into labelled product; expression in insect cells restored a production system, and <nuclear magnetic resonance> helped identify the product.<Identification of UBIAD1 as a novel human menaquinone-4 biosynthetic enzyme by Kimie Nakagawa and others>[Abstract, gene suppression, expression and product identification]{ref} Combining perturbation with chemical identification provides stronger evidence for an enzyme assignment than finding a similar-looking gene sequence alone.