Urea carboxylase, an avidin-sensitive enzyme catalyzing the ATP-dependent carboxylation of urea, has been shown to catalyze this reaction in a sequence of at least two steps. In the presence of all of the required carboxylation cofactors except urea, an enzyme-CO2 complex is formed. This complex was isolated by Sephadex chromatography and was capable, in the absence of added cofactors, of trans...

Acetyl-CoA carboxylases (ACCs) are crucial for the metabolism of fatty acids, making these enzymes important targets for the development of therapeutics against obesity, diabetes, and other diseases. The carboxyltransferase (CT) domain of ACC is the site of action of commercial herbicides, such as haloxyfop, diclofop, and sethoxydim. We have determined the crystal structures at up to 2.5-A reso...

Mesembryanthemum crystallinum is a model halophyte that switches from C3 photosynthesis to Crassulacean acid metabolism (CAM) upon extreme abiotic stresses. This study aimed investigate alkalinity-induced root transcriptome profiling in M. crystallinum. seedlings were treated with 50 mM sodium bicarbonate (NaHCO3; pH 7.5) and 90 NaHCO3 (pH 9.5) for 7 d, respectively. Alkalinity-induced differen...

Abstract The capture of CO 2 by carboxylases is key to sustainable biocatalysis and a carbon-neutral bio-economy, yet currently limited few naturally existing enzymes. Here, we developed glycolyl-CoA carboxylase (GCC), new-to-nature enzyme, combining rational design, high-throughput microfluidics microplate screens. During this process, GCC’s catalytic efficiency improved three orders magnitude...

Measurements of ribulose-1,5-bisphosphate carboxylase (RUBPCase) and phosphoenolpyruvate carboxylase (PEPCase) in several phytoplankton cultures and natural phytoplankton populations showed a positive correlation of photosynthesis with RUBPCase activity but not with PEPCase activity. Observed ratios of RUBPCase:PEPCase were high in log phase cultures when photosynthesis was maximal and low in s...

Biotin, a B-group vitamin, performs an essential metabolic function in all organisms. Rhizobia are alpha-proteobacteria with the remarkable ability to form a nitrogen-fixing symbiosis in combination with a compatible legume host, a process in which the importance of biotin biosynthesis and/or transport has been demonstrated for some rhizobia-legume combinations. Rhizobia have also been used to ...

The C4-photosynthetic carbon cycle is an elaborated addition to the classical C3-photosynthetic pathway, which improves solar conversion efficiency. The key enzyme in this pathway, phosphoenolpyruvate carboxylase, has evolved from an ancestral non-photosynthetic C3 phosphoenolpyruvate carboxylase. During evolution, C4 phosphoenolpyruvate carboxylase has increased its kinetic efficiency and redu...