title: Short-term regulation of nitrogenase activity by NH4+ in Rhodobacter capsulatus: multiple in vivo nitrogenase responses to NH4+ addition.
abstract: The photosynthetic bacterium Rhodobacter capsulatus has been shown to carry out nitrogenase "switch-off," a rapid, reversible inhibition of in vivo activity. Here, we demonstrate that highly nitrogen-limited cultures of both the wild-type strain and a draT draG mutant are capable of nitrogenase switch-off while moderately nitrogen-limited cultures show instead a "magnitude" response, with a decrease in in vivo nitrogenase activity that is proportional to the amount of added NH4+.
authors.affiliation: Département de Microbiologie et Immunologie, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: A F
authors.initials: AF
authors.lastname: Yakunin
authors.forename: P C
authors.initials: PC
authors.lastname: Hallenbeck
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D017136:Ion Transport; D009154:Mutation; D009699:N-Glycosyl Hydrolases; D009584:Nitrogen / Q000378:metabolism; D009591:Nitrogenase / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism / Q000494:pharmacology*; D016354:Rhodobacter capsulatus / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics
chemical_list: D000644:Quaternary Ammonium Compounds; D009591:Nitrogenase; D036002:ADP Ribose Transferases; C057637:dinitrogenase reductase ADP-ribosyltransferase; D006026:Glycoside Hydrolases; D009699:N-Glycosyl Hydrolases; C036091:ADP-ribosyl-(dinitrogen reductase) hydrolase; D009584:Nitrogen