IDENTIFICATION OF 2 SEQUENCE ELEMENTS ASSOCIATED WITH THE GENE ENCODING THE 24-KDA CRYSTALLINE COMPONENT IN BACILLUS-THURINGIENSIS SSP FUKUOKAENSIS - AN EXAMPLE OF TRANSPOSABLE ELEMENT ARCHAEOLOGY

A 6.5-kb fragment of plasmid DNA from Bacillus thuringiensis (Bt) ssp. fukuokaensis that encodes a 24-kDa crystalline component was analyzed to identify additional open reading frames (orfs). A novel Bt IS240-l ike element was found upstream of this gene and is considered to be a vestige of a once active insertion sequence due to a stop codon that i nterrupts the long orf encoding the putative transposase. This element was bounded by 17-bp terminal inverted repeats that defined the lengt h of the insertion sequence as 802 bp. Further upstream of this elemen t two tandem overlapping and out of phase open reading frames (orfX an d orfY) were identified which represent the first example of an IS150- like element in Bt containing both orfs. orfX and orfY are not bounded by terminal inverted repeats but are associated with a gene encoding a putative site-specific recombinase of a type found in Staphylococcus aureus Class II transposons but not previously in Bt. (C) 1997 Academ ic Press.