title: New genes implicated in the protection of anaerobically grown Escherichia coli against nitric oxide.
abstract: Nitric oxide produced by activated macrophages plays a key role as one of the immune system's weapons against pathogens. Because the lifetime of nitric oxide is short in aerobic conditions, whereas in anaerobic conditions the cytotoxic effects of nitric oxide are greatly increased as in the infection/inflammation processes, it is important to establish which systems are able to detoxify nitric oxide under anaerobic conditions. In the present work a new set of Escherichia coli K-12 genes conferring anaerobic resistance to nitric oxide is presented, namely the gene product of YtfE and a potential transcriptional regulator of the helix-turn-helix LysR-type (YidZ). The crucial role of flavohemoglobin for anaerobic nitric oxide protection is also demonstrated. Furthermore, nitric oxide is shown to cause a significant alteration of the global E. coli gene transcription profile that includes the increase of the transcript level of genes encoding for detoxification enzymes, iron-sulfur cluster assembly systems, DNA-repairing enzymes, and stress response regulators.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, Avenida da República (EAN), 2781-901 Oeiras, Portugal.
authors.forename: Marta C
authors.initials: MC
authors.lastname: Justino
authors.forename: João B
authors.initials: JB
authors.lastname: Vicente
authors.forename: Miguel
authors.initials: M
authors.lastname: Teixeira
authors.forename: Lígia M
authors.initials: LM
authors.lastname: Saraiva
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D004260:DNA Repair; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics*; D006420:Hemeproteins / Q000737:chemistry; D008264:Macrophages / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006420:Hemeproteins; D014157:Transcription Factors; C497161:YidZ protein, E coli; C497162:YtfE protein, E coli; C086193:flavohemoprotein, Bacteria; D009569:Nitric Oxide; D012313:RNA; D004247:DNA