title: Helicobacter pylori protein HP0222 belongs to Arc/MetJ family of transcriptional regulators.
abstract: Helicobacter pylori is a widespread human bacterial pathogen responsible for inducing gastric and duodenal ulcers and gastric cancers. To date, only 16 protein structures from this organism have been determined, and more than 30% of its 1500 protein functions remain unknown. We report the biochemical characterization, the tertiary structure determined by solution nuclear magnetic resonance (NMR) methods and the putative function of the previously uncharacterized protein HP0222 (JHP0208) from H. pylori. Recombinant HP0222 behaves as a dimer in crosslinking and size exclusion chromatography experiments. The structure consists of a ribbon-helix-helix fold characteristic of transcription factors of the Arc/MetJ family, which all bind DNA as higher order oligomers. Electrophoretic mobility shift assays reveal that HP0222 binds to double-stranded DNA. Previous studies have shown significant increases in transcription levels of HP0222 in response to acid shock and adherence to gastric epithelial cells. To assess possible involvement of HP0222 in acid resistance, we constructed and assayed an H. pylori HP0222 null mutant. We propose that HP0222 is a novel transcriptional regulator in H. pylori.
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37232, USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Popescu
authors.forename: Anne
authors.initials: A
authors.lastname: Karpay
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Israel
authors.forename: Richard M
authors.initials: RM
authors.lastname: Peek
authors.forename: Andrzej M
authors.initials: AM
authors.lastname: Krezel
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D017124:Conserved Sequence; D017931:DNA Primers; D004269:DNA, Bacterial / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D016480:Helicobacter pylori / Q000737:chemistry / Q000235:genetics*; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; C508546:HP0222 protein, Helicobacter pylori; D011994:Recombinant Proteins; D014157:Transcription Factors