InterPro domain: IPR045089

Prenyltransferases catalyze the covalent attachment of isoprenoid lipids (farnesyl or geranylgeranyl) to a cysteine near the C terminus of their substrates. This entry includes geranylgeranyl transferase type-1/2 subunit beta (Cdc43/Bet2) and farnesyltransferase subunit beta (Ram1). Cdc43/Bet2 catalyzes the transfer of a geranyl-geranyl moiety from geranyl-geranyl diphosphate to proteins having the C-terminal sequence Cys-Ile-Ile-Leu or Cys-Val-Leu-Leu [ 1 ]. Ram1 catalyzes the transfer of a farnesyl moiety from farnesyl diphosphate to a cysteine at the fourth position from the C terminus of several proteins having the C-terminal sequence Cys-aliphatic-aliphatic-X where X is Ser, Ala, Met, Cys, or Gln [ 2 ].

1. CDC43 and RAM2 encode the polypeptide subunits of a yeast type I protein geranylgeranyltransferase. J Biol Chem 267, 20589-93
2. RAM2, an essential gene of yeast, and RAM1 encode the two polypeptide components of the farnesyltransferase that prenylates a-factor and Ras proteins. Proc Natl Acad Sci U S A 88, 11373-7