title: MgtC as a horizontally-acquired virulence factor of intracellular bacterial pathogens: evidence from molecular phylogeny and comparative genomics.
abstract: MgtC is a virulence factor required for intramacrophage survival and growth in low Mg2+ medium in two pathogens that are not phylogenetically related, Salmonella typhimurium and Mycobacterium tuberculosis. In S. typhimurium, mgtC is carried by the SPI-3 pathogenicity island and hybridization studies have suggested that the distribution of mgtC among enterobacteria is limited. In the present study, we searched for the presence of mgtC-like sequences in eubacterial genomes. Analyses of MgtC-like proteins phylogeny and mgtC-like chromosomal context support the hypothesis that mgtC has been acquired by horizontal gene transfer repeatedly throughout bacterial evolution. In addition, the phylogenetic analysis revealed the existence of a subgroup of proteins, that includes the S. typhimurium and M. tuberculosis MgtC proteins, as well as MgtC-related proteins from other pathogens that are able to survive in macrophages, B. melitensis and Y. pestis. We propose that MgtC has a similar function in all these distantly related pathogens, most likely providing the ability to grow in a low Mg2+ environment.
authors.forename: Anne-Béatrice
authors.initials: AB
authors.lastname: Blanc-Potard
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Lafay
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D027682:Cation Transport Proteins / Q000235:genetics*; D023061:Gene Order; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial / Q000235:genetics; D016680:Genome, Bacterial; D023281:Genomics; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000472:pathogenicity*; D010802:Phylogeny; D012486:Salmonella typhimurium / Q000235:genetics* / Q000472:pathogenicity*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins; C093586:MgtC protein, Salmonella typhimurium