title: Role of NorR-like transcriptional regulators under nitrosative stress of the δ-proteobacterium, Desulfovibrio gigas.
abstract: NorR protein was shown to be responsible for the transcriptional regulation of flavorubredoxin and its associated oxidoreductase in Escherichia coli. Since Desulfovibrio gigas has a rubredoxin:oxygen oxidoreductase (ROO) that is involved in both oxidative and nitrosative stress response, a NorR-like protein was searched in D. gigas genome. We have found two putative norR coding units in its genome. To study the role of the protein designated as NorR1-like (NorR1L) in the presence of nitrosative stress, a norR1L null mutant of D. gigas was created and a phenotypic analysis was performed under the nitrosating agent GSNO. We show that under these conditions, the growth of both D. gigas mutants Δroo and ΔnorR1-like is impaired. In order to confirm that D. gigas NorR1-like may play identical function as the NorR of E. coli, we have complemented the E. coli ΔnorR mutant strain with the norR1-like gene and have evaluated growth when nitrosative stress was imposed. The growth phenotype of E. coli ΔnorR mutant strain was recovered under these conditions. We also found that induction of roo gene expression is completely abolished in the norR1L mutant strain of D. gigas subjected to nitrosative stress. It is identified in δ-proteobacteria, for the first time a transcription factor that is involved in nitrosative stress response and regulates the rd-roo gene expression.
authors: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
authors: Ana
authors: A
authors: Varela-Raposo
authors: Catarina
authors: C
authors: Pimentel
authors: Fabio
authors: F
authors: Morais-Silva
authors: Antonio
authors: A
authors: Rezende
authors: Jerônimo C
authors: JC
authors: Ruiz
authors: Claudina
authors: C
authors: Rodrigues-Pousada
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D045286:Desulfovibrio gigas / Q000235:genetics* / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D009566:Nitrates / Q000502:physiology*; D015538:Nitrosation; D010088:Oxidoreductases; D051922:PII Nitrogen Regulatory Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology; D010802:Phylogeny; D013312:Stress, Physiological / Q000235:genetics*; D014157:Transcription Factors / Q000145:classification / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D009566:Nitrates; D051922:PII Nitrogen Regulatory Proteins; D014157:Transcription Factors; C497876:glnG protein, E coli; D010088:Oxidoreductases; C081469:rubredoxin-oxygen oxidoreductase