title: A bi-site mechanism for Escherichia coli F1-ATPase accounts for the observed positive catalytic cooperativity.
abstract: Nucleotide binding to nucleotide-depleted F(1)-ATPase from Escherichia coli (EcF(1)) during MgATP hydrolysis in the presence of excess epsilon subunit has been studied using a combination of centrifugal filtration and column-centrifugation methods. The results show that nucleotide-binding properties of catalytic sites on EcF(1) are affected by the state of occupancy of noncatalytic sites. The ATP-concentration dependence of catalytic-site occupancy during MgATP hydrolysis demonstrates that a bi-site mechanism is responsible for the positive catalytic cooperativity observed during multi-site catalysis by EcF(1). The results suggest that a bi-site mechanism is a general feature of F(1) catalysis.
authors.affiliation: Department of Biochemistry and Molecular Biology, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Bulygin
authors.forename: Yakov M
authors.initials: YM
authors.lastname: Milgrom
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D025243:Bacterial Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis; D011756:Diphosphates / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D018038:Sodium Selenite / Q000737:chemistry
chemical_list: D011756:Diphosphates; D000255:Adenosine Triphosphate; D025243:Bacterial Proton-Translocating ATPases; D018038:Sodium Selenite