title: A physical and functional analysis of Tn917, a Streptococcus transposon in the Tn3 family that functions in Bacillus.
abstract: The erythromycin-resistance (Emr)-conferring transposon Tn917, first isolated in the genus Streptococcus, has in previous work been shown to function efficiently in the spore-forming species Bacillus subtilis, where it has been developed as a tool for identifying and studying sporulation genes. In the present work, a physical analysis of Tn917 was undertaken, including detailed restriction mapping, chemical DNA sequencing, heteroduplex studies, and Southern hybridization analysis, as a first step in understanding the genetic organization of this useful insertion element. The location and transcriptional orientation of the transposon-borne erm gene (the gene responsible for the Emr phenotype) have been determined, and a partial sequence of DNA 5' to the coding sequence of this gene indicates that its inducibility is probably the result of "translational attenuation," a mechanism known to be responsible for the regulation of at least two other gram-positive erm genes. Restriction mapping and heteroduplex analysis have revealed extensive homology between Tn917 and the Staphylococcus transposon Tn551, throughout virtually their entire lengths, and DNA sequencing studies have revealed a remarkably high degree of sequence correspondence within the terminal inverted repeats of Tn917, Tn551 and the gram-negative transposon Tn3. Tn917 was also shown to generate a 5-bp duplication upon insertion, as do Tn3 and Tn551 (and all of the other Tn3-related elements studied thus far), strengthening the conclusion that these three transposons are members of a highly dispersed family of related insertion elements which populate both gram-positive and gram-negative genera.
mesh_terms: D001407:Bacillus / Q000235:genetics*; D001483:Base Sequence; D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000494:pharmacology*; D005796:Genes; D005809:Genes, Regulator; D014176:Protein Biosynthesis; D012091:Repetitive Sequences, Nucleic Acid; D013045:Species Specificity; D013291:Streptococcus / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004917:Erythromycin; D004262:DNA Restriction Enzymes