enzyme is unique in the protein prenyltransferase family, consisting protein farnesyltransferase, EC 2.5.1.58, protein geranylgeranyltransferase type I, EC 2.5.1.59 and Rab geranylgeranyltransferase
enzyme is unique in the protein prenyltransferase family, consisting protein farnesyltransferase, EC 2.5.1.58, protein geranylgeranyltransferase type I, EC 2.5.1.59 and Rab geranylgeranyltransferase
mechanism, geranylgeranyl diphosphate first acts as an allosteric regulator of enzyme, second acts as the phosphoisoprenoid donor in the prenylation reaction and third senses the completion of catalysis and concomitantly triggers substrate release by increasing the dissociation rate of the product
mammalian enzyme have revealed two alternative pathways for the assembly of catalytic complex. The classical pathway: the Rab protein forms a stable complex with REP. Enzyme covalently attaches the geranylgeranyl groups to two C-terminal cysteines of the Rab protein. Upon prenylation, the Rab/REP complex remains tightly associated with the enzyme until binding of a new molecule of isoprenoid decreases its affinity for the prenylated complex. The prenylated complex dissociated from enzyme and delivers Rab protein to its target membrane. In the alternative pathway, enzyme and REP form a tight complex in the presence of the phosphoisoprenoid. This complex is catalytically competent and can recruit and prenylate Rab protein.
mammalian enzyme have revealed two alternative pathways for the assembly of catalytic complex. The classical pathway: the Rab protein forms a stable complex with REP. Enzyme covalently attaches the geranylgeranyl groups to two C-terminal cysteines of the Rab protein. Upon prenylation, the Rab/REP complex remains tightly associated with the enzyme until binding of a new molecule of isoprenoid decreases its affinity for the prenylated complex. The prenylated complex dissociated from enzyme and delivers Rab protein to its target membrane. In the alternative pathway, enzyme and REP form a tight complex in the presence of the phosphoisoprenoid. This complex is catalytically competent and can recruit and prenylate Rab protein.
mechanism, phosphoisoprenoid acts both as a substrate and as a sensor governing the kinetics of protein protein interactions in the double prenylation reaction
enzyme is unique in the protein prenyltransferase family, consisting protein farnesyltransferase, EC 2.5.1.58, protein geranylgeranyltransferase type I, EC 2.5.1.59 and Rab geranylgeranyltransferase