The occurrence of protein farnesyltransferase has been demonstrated in
spinach. The enzyme transferred different prenyl groups to the nonape
ptide acceptor. All-trans isoprenoid diphosphates were utilized most e
fficiently in contrast to long-chain mainly cis-polyprenyl diphosphate
s and dolichyl diphosphates. The activity of the enzyme was stimulated
by divalent cations. The presence of protein farnesyltransferase acti
vity in several plant species has been confirmed.