title: The ATP hydrolyzing transcription activator phage shock protein F of Escherichia coli: identifying a surface that binds sigma 54.
abstract: Members of the protein family called ATPases associated with various cellular activities (AAA(+)) play a crucial role in transforming chemical energy into biological events. AAA(+) proteins are complex molecular machines and typically form ring-shaped oligomeric complexes that are crucial for ATPase activity and mechanism of action. The Escherichia coli transcription activator phage shock protein F (PspF) is an AAA(+) mechanochemical enzyme that functions to sense and relay the energy derived from nucleoside triphosphate hydrolysis to catalyze transcription by the sigma(54)-RNA polymerase. Closed promoter complexes formed by the sigma(54)-RNA polymerase are substrates for the action of PspF. By using a protein fragmentation approach, we identify here at least one sigma(54)-binding surface in the PspF AAA(+) domain. Results suggest that ATP hydrolysis by PspF is coupled to the exposure of at least one sigma(54)-binding surface. This nucleotide hydrolysis-dependent presentation of a substrate binding surface can explain why complexes that form between sigma(54) and PspF are transient and could be part of a mechanism used generally by other AAA(+) proteins to regulate activity.
authors.affiliation: Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bordes
authors.forename: Siva R
authors.initials: SR
authors.lastname: Wigneshweraraj
authors.forename: Jörg
authors.initials: J
authors.lastname: Schumacher
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.forename: Matthew
authors.initials: M
authors.lastname: Chaney
authors.forename: Martin
authors.initials: M
authors.lastname: Buck
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001483:Base Sequence; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D006868:Hydrolysis; D015151:Immunoblotting; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D051877:RNA Polymerase Sigma 54; D012808:Sigma Factor / Q000378:metabolism*; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C098954:PspF protein, E coli; D012808:Sigma Factor; D015534:Trans-Activators; C497751:rpoN protein, E coli; D000255:Adenosine Triphosphate; D004247:DNA; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54; D003850:Deoxyribonuclease I; D001616:beta-Galactosidase; D000251:Adenosine Triphosphatases