title: Role for the Salmonella flavohemoglobin in protection from nitric oxide.
abstract: Hemoglobin homologs are being identified in an expanding number of unicellular prokaryotic and eukaryotic organisms. Many of these hemoglobins are twodomain proteins that possess a flavin-containing reductase in their C terminus. Determination of a function for these flavohemoglobins has been elusive. A Salmonella typhimurium strain harboring a deletion in the flavohemoglobin gene shows no difference in growth under oxidative stress conditions but displays an increased sensitivity to acidified nitrite and S-nitrosothiols, both of which produce nitric oxide. The effect is seen aerobically or anaerobically, indicating that oxygen is not required for flavohemoglobin function. These results suggest a role for the bacterial flavohemoglobins that is independent of oxygen metabolism and provide evidence for a bacterial route of protection from nitric oxide that is distinct from oxidative stress responses.
authors.affiliation: Howard Hughes Medical Institute, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Crawford
authors.forename: D E
authors.initials: DE
authors.lastname: Goldberg
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D017353:Gene Deletion; D006420:Hemeproteins / Q000235:genetics / Q000502:physiology*; D006454:Hemoglobins / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D006420:Hemeproteins; D006454:Hemoglobins; C086193:flavohemoprotein, Bacteria; D009569:Nitric Oxide