has role has_role has role gene as virulence factor in pathogen gene mutant attenuated in host cell gene mutant attenuated in host has role has_role has role macrophage macrophage 巨噬细胞 Mus musculus Mus musculus 小家鼠 Brucella abortus 2308 Brucella melitensis biovar Abortus 2308 protein-coding gene of Brucella melitensis biovar Abortus 2308 BAB2_0067 20140406 359391 3827981 BAB2_0067 Bin Zhao, Oliver He II NCBI-supplied PMID: 16299333 WEB: http://www.ncbi.nlm.nih.gov/gene protein-coding type IV secretion system protein VirB2 MUTATION: The Brucella abortus virB operon, encoding a type IV secretion system (T4SS), is required for intracellular replication and persistent infection in the mouse model. The products of the first two genes of the virB operon, virB1 and virB2, are predicted to be localized at the bacterial surface. Both mutants were shown to be nonpolar, as demonstrated by their ability to express the downstream gene virB5 during stationary phase of growth in vitro. Both VirB1 and VirB2 were essential for intracellular replication in J774 macrophages. The nonpolar virB2 mutant was unable to cause persistent infection in the mouse model, demonstrating the essential role of VirB2 in the function of the T4SS apparatus during infection [PMID:15322008]. Polar mutations in the virB1 to virB2 intergenic region or in virB2 reduced the detection of VirB5 to a greater extent than they did that of VirB12. A virB1 mutation also eliminates the transcription of virB12 in B suis [PMID:15322008]. 1760 virulence factor gene role