Isolation and characterization of IS1409, an insertion element of 4-chlorobenzoate-degrading Arthrobacter sp strain TM1, and development of a system for transposon mutagenesis

A new insertion element of 1,449 bp with 25-bp perfect terminal repeats, de signated IS1409, was identified in the chromosome of 4-chlorobenzoate-degra ding Arthrobacter sp, strain TM1 NCIB12013, Upon insertion, IS1409 causes a target duplication of 8 bp, IS1409 carries only a single open reading fram e of 435 codons encoding the transposase TnpA, Both TnpA and the overall or ganization of IS1409 are highly similar to those of some related insertion elements of the ISL3 group (J, Mahillon and M, Chandler, Microbiol. Mel. Bi ol, Rev. 62:725-774, 1998), IS1409 was also found in other 4-chlorobenzoate -degrading Arthrobacter strains and Micrococcus luteus. Based on IS1409, a series of transposons carrying resistance genes for chloramphenicol and gen tamicin were constructed. These transposons were used to demonstrate transp osition events in vivo and to mutagenize Arthrobacter sp. strains.