How many carbon atoms are present in the farnesyl lipid modification?
Prenylation adds isoprenoid lipids derived from mevalonate pathway to cysteine in CAAX motif. Two major forms exist: 15-carbon farnesyl comprising three isoprene units and 20-carbon geranylgeranyl comprising four isoprene units. Farnesyl pyrophosphate synthesized from isopentenyl pyrophosphate and dimethylallyl pyrophosphate serves donor for farnesyltransferase FTase, while geranylgeranyl pyrophosphate serves donor for geranylgeranyltransferase I and II. Farnesyl group contains 15 carbon atoms arranged as 2E,6E-farnesyl with three double bonds providing hydrophobic moiety about 10 angstrom len
Ref: Zhang & Casey, Annu Rev Biochem 1996, Prenyl groups; Wang & Casey 2016, Prenylation.
