title: FixL-like sensor FlbS of Brucella abortus binds haem and is necessary for survival within eukaryotic cells.
abstract: Replication of Brucella inside eukaryotic cells is essential for pathogenesis, and successful infection requires rapid adaptation to the intracellular milieu. Close relatives of Brucella use the two-component system FixLJ to survive inside the host. We aimed to identify a homologous sensor in Brucella abortus. A predicted protein with transmembrane and conserved histidine kinase domains was identified as the Fix-like Brucella sensor, FlbS. Although it lacks the PAS domain, recombinant FlbS binds haem in vitro. An internal in-frame deletion in flbS severely decreased B. abortus survival inside professional and non-professional phagocytes. This phenotype was reverted by genetic complementation. These results indicate the critical role of this haemoprotein in the intracellular lifestyle of Brucella.
authors: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
authors: Mara S
authors: MS
authors: Roset
authors: Marta A
authors: MA
authors: Almirón
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002003:Brucella abortus / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D002460:Cell Line; D015169:Colony Count, Microbial; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics; D017353:Gene Deletion; D015870:Gene Expression; D005816:Genetic Complementation Test; D006367:HeLa Cells; D006418:Heme / Q000378:metabolism*; D006420:Hemeproteins / Q000235:genetics / Q000378:metabolism*; D000071677:Histidine Kinase; D006801:Humans; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D050296:Microbial Viability; D010802:Phylogeny; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D006420:Hemeproteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; D006418:Heme; C067929:FixL protein, Bacteria; D000071677:Histidine Kinase
keywords: Brucella; FixL; Haemoprotein; Intracellular survival; Two-component system