Identification and Characterization of IS 1411 , a New Insertion Sequence Which Causes Transcriptional Activation of the Phenol Degradation Genes in Pseudomonas putida

Abstract

ABSTRACT A new insertion sequence (IS element), IS 1411 , was identified downstream of the phenol degradation genes pheBA that originated from plasmid DNA of Pseudomonas sp. strain EST1001. According to sequence analysis, IS 1411 belongs to a new family of IS elements that has recently been named the ISL 3 family (J. Mahillon and M. Chandler, Microbiol. Mol. Biol. Rev. 62:725–774, 1998). IS 1411 generates 8-bp duplication of the target DNA and carries 24-bp inverted repeats (IRs), highly homologous to the IRs of other IS elements belonging to this family. IS 1411 was discovered as a result of insertional activation of promoterless pheBA genes in Pseudomonas putida due to the presence of outward-directed promoters at the left end of IS 1411 . Both promoters located on the IS element have sequences that are similar to the consensus sequence of Escherichia coli ς 70 . IS 1411 can produce IS circles, and the circle formation is enhanced when two copies of the element are present in the same plasmid.