title: Phosphoribulokinase mediates nitrogenase-induced carbon dioxide fixation gene repression in Rhodobacter sphaeroides.
abstract: In many organisms there is a balance between carbon and nitrogen metabolism. These observations extend to the nitrogen-fixing, nonsulfur purple bacteria, which have the classic family of P(II) regulators that coordinate signals of carbon and nitrogen status to regulate nitrogen metabolism. Curiously, these organisms also possess a reverse mechanism to regulate carbon metabolism based on cellular nitrogen status. In this work, studies in Rhodobacter sphaeroides firmly established that the activity of the enzyme that catalyses nitrogen fixation, nitrogenase, induces a signal that leads to repression of genes encoding enzymes of the Calvin-Benson-Bassham (CBB) CO2 fixation pathway. Additionally, genetic and metabolomic experiments revealed that NADH-activated phosphoribulokinase is an intermediate in the signalling pathway. Thus, nitrogenase activity appears to be linked to cbb gene repression through phosphoribulokinase.
authors: Department of Microbiology, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210-1292, USA.
authors: Ryan M
authors: RM
authors: Farmer
authors: Department of Microbiology, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210-1292, USA.
authors: F Robert
authors: FR
authors: Tabita
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D055442:Metabolome; D009584:Nitrogen / Q000378:metabolism; D009591:Nitrogenase / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D012242:Rhodobacter sphaeroides / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D002245:Carbon Dioxide; D009591:Nitrogenase; D017853:Phosphotransferases (Alcohol Group Acceptor); C022390:phosphoribulokinase; D009584:Nitrogen