title: Free RNA-dependent ATPase activity of transcription termination factor Rho: a model of cyclic dissociation and reassembly of Rho protein.
abstract: RNA-dependent ATPase activity of Rho + and two mutant proteins Rho15 and Rho301 was studied. It was shown that monomeric Rho forms oligomers in the presence of ATP. This ATP-induced structural change of Rho allows protection of the protein from heat inactivation. Poly(C), which highly activates Rho ATPase, was found to potentiate heat inactivation of Rho301, but no Rho + and Rho15, only under optimal conditions of ATP hydrolysis. It was also shown that Rho301 is defective in interaction with RNA. The molecular model postulating that Rho-catalysed ATP hydrolysis with free RNA involves the cyclic process of protein dissociation and reassembly is postulated.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D007700:Kinetics; D046911:Macromolecular Substances; D009154:Mutation; D011066:Poly C / Q000494:pharmacology; D012234:Rho Factor / Q000235:genetics / Q000378:metabolism*; D013816:Thermodynamics; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D012234:Rho Factor; D014157:Transcription Factors; D011066:Poly C; D000251:Adenosine Triphosphatases; C027900:RNA-dependent ATPase