Isolation and Characterization of IS 1409 , an Insertion Element of 4-Chlorobenzoate-Degrading Arthrobacter sp. Strain TM1, and Development of a System for Transposon Mutagenesis

Abstract

ABSTRACT A new insertion element of 1,449 bp with 25-bp perfect terminal repeats, designated IS 1409 , was identified in the chromosome of 4-chlorobenzoate-degrading Arthrobacter sp. strain TM1 NCIB12013. Upon insertion, IS 1409 causes a target duplication of 8 bp. IS 1409 carries only a single open reading frame of 435 codons encoding the transposase TnpA. Both TnpA and the overall organization of IS 1409 are highly similar to those of some related insertion elements of the ISL 3 group (J. Mahillon and M. Chandler, Microbiol. Mol. Biol. Rev. 62:725–774, 1998). IS 1409 was also found in other 4-chlorobenzoate-degrading Arthrobacter strains and Micrococcus luteus . Based on IS 1409 , a series of transposons carrying resistance genes for chloramphenicol and gentamicin were constructed. These transposons were used to demonstrate transposition events in vivo and to mutagenize Arthrobacter sp. strains.