Kinetic studies on the prenyl chain elongation by undecaprenyl diphosphate synthase with artificial substrate homologues.
In the undecaprenyl diphosphate synthase reaction, an allylic substrate homologue, (2Z,6E,10E)-4-methyl-geranylgeranyl diphosphate was found to be a potent competitive inhibitor against the allylic primer, (2Z,6E,10E)-geranylgeranyl diphosphate. On the other hand, it acted as a strong noncompetitive inhibitor against isopentenyl diphosphate. On the basis of these facts, the topology of the substrate-binding sites as well as the reason why the synthase reaction with (E)-3-methyl-3-pentenyl diphosphate always stops completely at the first stage of condensation, yielding an allylic diphosphate with a methyl group at the 4-position, are discussed.
Ohnuma
S
S
Chemical Research Institute of Non-Aqueous Solutions, Tohoku University, Sendai, Japan.
Koyama
T
T
Ogura
K
K
D019883:Alkyl and Aryl Transferases; D001412:Bacillus subtilis / Q000201:enzymology; D001665:Binding Sites; D007700:Kinetics; D011106:Polyisoprenyl Phosphates / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014166:Transferases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D011106:Polyisoprenyl Phosphates; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C023266:undecaprenyl pyrophosphate synthetase