IS421, a new insertion sequence in Escherichia coli

Abstract

The nucleotide sequence of a new insertion sequence (IS) in Escherichiu co/i, IS421, was determined. It is 1340 bp long and contains inverted repeats of 22 bp at its termini. It is flanked by 13 bp direct repeats apparently generated upon insertion. There are two ORFs longer than 200 bp in IS421. One can encode a polypeptide of 371 amino acids (aa) and the other, which is on the other strand, can encode a polypeptide of 102 aa. The C-terminal part of the 371 aa polypeptide shows some homology to that of transposases encoded in some other known IS elements. The copy number of IS421 in chromosomal DNA was 4 for E. coli K-12 and B, and 5 for E. coli C, as determined by the Southern hybridization of restriction fragments.

IS1151, an IS-like element of Clostridium perfringens

“…This sequence (1696 bp) possesses two 23 bp stretches, one at each extremity, which constitute a perfect inverted repeat. A search in the EMBL data bank revealed homologies with the IS231 family of Bacillus thurigiensis insertion elements (4,5), and with IS4, IS186, and IS421 insertion sequences of E. coli (6,7,8). The inverted repeats of ISi 151 are homologous to the corresponding sequences of the IS231 and IS4 insertion elements but diverge from those of IS186 and of IS421.…”

Comprehensive de novo structure prediction in a systems-biology context for the archaea Halobacterium sp. NRC-1

“…We find several matches within this region to the Pfam transposase DDE (PF01609) family of proteins, first isolated from bacteriophage lambda [66]. We also find two matches to phage integrases: VNG6112H matches Pfam integrase family PF00589, while two Rosetta-predicted structures for VNG6117H both match a phage integrase fold (1asu00).…”