A physical and functional analysis of Tn917, a Streptococcus transposon in the Tn3 family that functions in Bacillus

Plasmid. 1984 Sep;12(2):119-38. doi: 10.1016/0147-619x(84)90058-1.


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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacillus / genetics*
  • Base Sequence
  • Chromosome Mapping
  • DNA Restriction Enzymes
  • DNA Transposable Elements*
  • DNA, Bacterial / genetics
  • Drug Resistance, Microbial
  • Erythromycin / pharmacology*
  • Genes
  • Genes, Regulator
  • Protein Biosynthesis
  • Repetitive Sequences, Nucleic Acid
  • Species Specificity
  • Streptococcus / genetics*


  • DNA Transposable Elements
  • DNA, Bacterial
  • Erythromycin
  • DNA Restriction Enzymes

Associated data

  • GENBANK/K02677
  • GENBANK/K02678