Reaction catalyzed by protein geranylgeranyltransferase type I (2.5.1.59)
+
Rac GTPase-cysteine
=
S-geranylgeranyl-Rac GTPase
+
geranylgeranyl diphosphate
+
Rac GTPase-cysteine
=
S-geranylgeranyl-Rac GTPase
+
diphosphate