title: Crystal structure of the central and C-terminal domain of the sigma(54)-activator ZraR.
abstract: The sigma(54)-dependent transcription in bacteria is associated with various stress and growth conditions. Activators of the sigma(54) protein contain a central domain belonging to the AAA+ superfamily of ATPases, members of which function in diverse cellular processes in both prokaryotic and eukaryotic cells. We describe the X-ray structure of an N-terminal domain deletion of the ZraR protein from Salmonella typhimurium, which is a homologue of the general nitrogen regulatory protein NtrC, at 3A resolution. The structure reveals a hexameric ring that is typical for AAA+ containing proteins but which differs from the heptameric ring found in the crystal structure of the AAA+ domain of NtrC1 from Aquifex aeolicus. The dimerisation interface between DNA-binding domains observed in the crystal structure suggests that dodecamers, rather than hexamers, might be the functionally important oligomer.
authors: European Molecular Biology Laboratory Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany.
authors: László
authors: L
authors: Sallai
authors: Paul A
authors: PA
authors: Tucker
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D001665:Binding Sites; D016384:Consensus Sequence; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry*; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051877:RNA Polymerase Sigma 54; D012486:Salmonella typhimurium / Q000737:chemistry; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000737:chemistry*; D015534:Trans-Activators
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012808:Sigma Factor; D015534:Trans-Activators; C497751:rpoN protein, E coli; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54