The Corynebacterium xerosis composite transposon Tn5432 consists of two identical insertion sequences, designated IS1249, flanking the erythromycin resistance gene ermCX

Plasmid. 1995 Sep;34(2):119-31. doi: 10.1006/plas.1995.9995.


Analysis of the 50-kb R-plasmid pTP10 from the clinical isolate Corynebacterium xerosis M82B revealed that the erythromycin resistance gene, ermCX, is located on a 4524-bp composite transposable element, Tn5432. The ends of Tn5432 are identical, direct repeats of an insertion sequence, designated IS1249, encoding a putative transposase of the IS256 family. IS1249 consists of 1385 bp with 45/42 imperfect terminal inverted repeats. The nucleotide sequence of the 1754-bp Tn5432 central region is 99% identical to the previously sequenced erythromycin resistance region of the Corynebacterium diphtheriae plasmid pNG2. It encodes the erythromycin resistance gene, ermCX, and an ORF homologous to the amino-terminal end of the transposase of IS31831 from Corynebacterium glutamicum. Transposons with regions flanking the insertion sites were recovered from the C. glutamicum chromosome by a plasmid rescue technique. Insertion of Tn5432 created 8-bp target site duplications. A Tn5432-induced isoleucine/valine-auxotrophic mutant was found to carry the transposon in the 5' region of the ilvBNC cluster; in pTP10 the transposon is inserted in a region similar to replication and partitioning functions of the Enterococcus faecalis plasmid pAD1 and the Agrobacterium tumefaciens plasmid pTAR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology
  • Base Sequence
  • Chromosome Mapping
  • Cloning, Molecular
  • Corynebacterium / drug effects
  • Corynebacterium / genetics*
  • Corynebacterium diphtheriae / drug effects
  • Corynebacterium diphtheriae / genetics
  • DNA Nucleotidyltransferases / genetics
  • DNA Replication / genetics
  • DNA Transposable Elements*
  • DNA, Bacterial / genetics
  • Drug Resistance, Microbial / genetics
  • Erythromycin / pharmacology
  • Genes, Bacterial*
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Repetitive Sequences, Nucleic Acid
  • Transposases


  • Anti-Bacterial Agents
  • DNA Transposable Elements
  • DNA, Bacterial
  • Erythromycin
  • DNA Nucleotidyltransferases
  • Transposases

Associated data

  • GENBANK/U21300