Biotin-containing 3-methylcrotonyl coenzyme A (MC-CoA) carboxylase (MCCase) and geranyl-CoA (G-CoA) carboxylase (GCCase) from Pseudomonas aeruginosa were expressed as His-tagged recombinant proteins in Escherichia coli. Both native and recombinant MCCase and GCCase showed pH and temperature optima of 8.5 and 37 degrees C. The apparent K(0.5) (affinity constant for non-Michaelis-Menten kinetics ...

Ketoacyl synthases (KSs) catalyze condensing reactions combining acyl-CoA or acylacyl carrier protein (ACP) with malonyl-CoA to form 3-ketoacyl-CoA, or with malonyl-ACP to form 3-ketoacyl-ACP. In each case the resulting acyl chain is two carbon atoms longer than before, and CO2 and either CoA or ACP are formed. KSs also join other activated molecules in the polyketide synthesis cycle. Our class...

Studies of ribulose-1,5-bisphosphate (RuBP) carboxylase from taxonomically diverse plants show that the enzyme from C(3) and crassulacean acid metabolism pathway species exhibits lower K(m)(CO(2)) values (12-25 micromolar) than does that from C(4) species (28-34 micromolar). RuBP carboxylase from aquatic angiosperms, an aquatic bryophyte, fresh water and marine algae has yielded consistently hi...

The high rates of photosynthesis and the carbon concentrating mechanism (CCM) in C4 plants is initiated by enzyme phosphoenolpyruvate (PEP) carboxylase (PEPC). flow inorganic into CCM driven PEPC's affinity for bicarbonate (KHCO3 ), which can be rate limiting when atmospheric CO2 availability restricted due to low stomatal conductance. We hypothesize that natural variation KHCO3 across specific...