title: Horizontal gene transfer in the evolution of group A streptococcal emm-like genes: gene mosaics and variation in Vir regulons.
abstract: Most M type 5 group A streptococcal strains were found to contain a single emm-like gene between virR and scpA (the Vir regulon), but two distinct emm-like genes were identified in the Vir regulon of the M5 strain NCTC8193. The complete sequences of both of these genes were determined. One, called emm5.8193, was shown to be a minor variant of the previously described emm5 gene from strain Manfredo. The second, designated enn5.8193, expresses an IgG-binding protein when cloned in Escherichia coli. A comparison of enn5.8193 with emm-like gene sequences from other strains indicated that it has a mosaic structure, consisting of distinct segments originating from emm-like genes in different OF+ and OF- strains. These data provide the first clear evidence that the horizontal transfer of emm-like sequences between distinct strains contributes to the evolution of group A streptococcal emm-like genes and Vir regulons.
authors.affiliation: Department of Microbiology, University of Newcastle upon Tyne Medical School, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Whatmore
authors.forename: M A
authors.initials: MA
authors.lastname: Kehoe
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D017931:DNA Primers; D004251:DNA Transposable Elements; D004926:Escherichia coli; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D014644:Genetic Variation; D006801:Humans; D008969:Molecular Sequence Data; D009030:Mosaicism; D016133:Polymerase Chain Reaction; D018085:Regulon; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D004251:DNA Transposable Elements; C068267:mry protein, Streptococcus pyogenes; D004247:DNA