title: Investigation of the translation-initiation factor IF2 gene, infB, as a tool to study the population structure of Streptococcus agalactiae.
abstract: The sequence of infB, encoding the prokaryotic translation-initiation factor 2 (IF2), was determined in eight strains of Streptococcus agalactiae (group B streptococcus) and an alignment revealed limited intraspecies diversity within S. agalactiae. The amino acid sequence of IF2 from S. agalactiae and from related species were aligned and revealed an interspecies conserved central and C-terminal part, and an N-terminal part that is highly variable in length and amino acid sequence. The diversity and relationships in a collection of 58 genetically distinct strains of S. agalactiae were evaluated by comparing a partial sequence of infB. A total of six alleles were detected for the region of infB analysed. The alleles correlated with the separation of the same strains of S. agalactiae into major evolutionary lineages, as shown in previous work. The partial sequences of infB were furthermore used in phylogenetic analyses of species closely related to S. agalactiae, yielding an evolutionary tree which had a topology similar to a tree constructed using 16S rRNA sequences from the same species.
authors.affiliation: Department of Biostructural Chemistry, Institute of Molecular and Structural Biology, Aarhus University, Gustav Wiedsvej 10C, DK-8000 Aarhus C, Denmark1.
authors.forename: Jakob
authors.initials: J
authors.lastname: Hedegaard
authors.affiliation: Department of Medical Microbiology and Immunology, The Bartholin Building, Aarhus University, DK-8000 Aarhus C, Denmark2.
authors.forename: Majbritt
authors.initials: M
authors.lastname: Hauge
authors.affiliation: Department of Biostructural Chemistry, Institute of Molecular and Structural Biology, Aarhus University, Gustav Wiedsvej 10C, DK-8000 Aarhus C, Denmark1.
authors.forename: Jeppe
authors.initials: J
authors.lastname: Fage-Larsen
authors.affiliation: Department of Biostructural Chemistry, Institute of Molecular and Structural Biology, Aarhus University, Gustav Wiedsvej 10C, DK-8000 Aarhus C, Denmark1.
authors.forename: Kim Kusk
authors.initials: KK
authors.lastname: Mortensen
authors.affiliation: Department of Medical Microbiology and Immunology, The Bartholin Building, Aarhus University, DK-8000 Aarhus C, Denmark2.
authors.forename: Mogens
authors.initials: M
authors.lastname: Kilian
authors.affiliation: Department of Biostructural Chemistry, Institute of Molecular and Structural Biology, Aarhus University, Gustav Wiedsvej 10C, DK-8000 Aarhus C, Denmark1.
authors.forename: Hans Uffe
authors.initials: HU
authors.lastname: Sperling-Petersen
authors.affiliation: Department of Medical Microbiology and Immunology, The Bartholin Building, Aarhus University, DK-8000 Aarhus C, Denmark2.
authors.forename: Knud
authors.initials: K
authors.lastname: Poulsen
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D014644:Genetic Variation; D006801:Humans; D008969:Molecular Sequence Data; D010448:Peptide Initiation Factors / Q000235:genetics*; D010802:Phylogeny; D039881:Prokaryotic Initiation Factor-2; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D012269:Ribosomal Proteins / Q000235:genetics; D016415:Sequence Alignment; D013045:Species Specificity; D013292:Streptococcus agalactiae / Q000145:classification / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D010448:Peptide Initiation Factors; D039881:Prokaryotic Initiation Factor-2; D012336:RNA, Ribosomal, 16S; D012269:Ribosomal Proteins