title: IS257 from Staphylococcus aureus: member of an insertion sequence superfamily prevalent among gram-positive and gram-negative bacteria.
abstract: The nucleotide sequences for the IS257 family of insertion sequences from Staphylococcus aureus were compared with those of the ISS1 family from Streptococcus lactis and the IS15 family which is widespread amongst Gram-negative bacteria. These elements have a striking degree of similarity in both their putative transposase polypeptide sequences and their nucleotide sequences (40 to 64% between pairs), including 12 out of 14 bp conservation in their terminal inverted repeats. The evolutionary distance between the IS15 family and the IS257 and ISS1 families of Gram-positive origin is approximately twice that between the IS257 and ISS1 families. Analysis of base substitutions in the three sequences has provided insights into the effect of selection for the G + C content of immigrant genes to conform to that of their hosts, and into the evolution of biases in overall amino acid composition of cellular proteins in prokaryotes and eukaryotes. The IS257, ISS1, IS15 families form a superfamily of insertion sequences that has been involved in the spread of a number of antimicrobial resistance determinants in Gram-positive and Gram-negative pathogens.
authors.affiliation: Department of Microbiology, Monash University, Clayton, Victoria, Australia.
authors.forename: D A
authors.initials: DA
authors.lastname: Rouch
authors.forename: R A
authors.initials: RA
authors.lastname: Skurray
mesh_terms: D000595:Amino Acid Sequence; D001482:Base Composition; D001483:Base Sequence; D005075:Biological Evolution; D003062:Codon; D003596:Cytosine; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D005798:Genes, Bacterial; D006090:Gram-Negative Bacteria / Q000235:genetics; D006094:Gram-Positive Bacteria / Q000235:genetics; D006147:Guanine; D013294:Lactococcus lactis / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D009713:Nucleotidyltransferases / Q000235:genetics; D012641:Selection, Genetic; D012689:Sequence Homology, Nucleic Acid; D013211:Staphylococcus aureus / Q000235:genetics*; D019895:Transposases
chemical_list: D003062:Codon; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D006147:Guanine; D003596:Cytosine; D009713:Nucleotidyltransferases; D019895:Transposases