IS1394 FROM PSEUDOMONAS ALCALIGENES NCIB-9867 - IDENTIFICATION AND CHARACTERIZATION OF A MEMBER OF THE IS30 FAMILY OF INSERTION ELEMENTS

A new insertion sequence designated IS1394 was isolated from Pseudomon as alcaligenes NCIB 9867 (P25X) by entrapment in plasmid pUCD800 which carries the Bacillus subtilis sacB and sacR genes. The 1100-bp sequen ce contains 27-bp inverted repeats with 4 bp mismatch and has one long open reading frame, spanning 92.1% of the entire IS: The deduced 338 amino-acid sequence demonstrated homology (varying from 65% to 78% sim ilarity and 36-67% identity) to transposases encoded by the IS30 famil y of IS elements. Comparison of four different IS-sacB junction sequen ces showed that IS1394 generated 3-bp direct repeats of target DNA upo n insertion. IS1394 is present in at least 10 copies in the P25X genom e but none was detected in its endogenous plasmid pRA2. Hybridization experiments revealed that the distribution of IS1394 is limited to clo sely related strains, being present in three copies in Pseudomonas put ida NCIB 9869 (P35X) and two copies in Pseudomonas alcaligenes ATCC ty pe strain (ATCC 14904).