IS982 family

Members of this family (Fig. A) are restricted at present to Gram-positive bacteria. They are between 962 and 1026 bp in length and carry similar terminal IRs of between 18 and 35 bp (Fig. B). Their termini are highly conserved and generally start with 5'-ACCC (Fig.). As for several other IS elements, IS982B from Lactococcus lactis has been shown to provide a -35 hexamer in its right terminal IR which is capable of forming a hybrid promoter with a resident -10 sequence located at the target site (295). ISSa4 from Streptococcus agalactiae generates 7 bp (or perhaps 9 bp) flanking DRs (449) and ISCce1 from Clostridium cellulovorans is flanked by 7 bp repeats (465). Family members encode a single open reading frame capable of specifying a protein of between 271 and 296 amino acids which exhibit between 33% and 44% amino acid identity. A possible DDE motif is also apparent but does not include a convincing conserved downstream K/R residue. Little is known about the transposition of these elements.

Figure . The IS982 family. A) Dendrogram based on transposase alignments. B) Terminal inverted repeats.

Mahillon J.  and  Chandler M.  (1998) Microbiology and Molecular Biology Reviews.  62 : 725-774
Chandler, M. and Mahillon, J.(2002) Insertion Sequences Revisited Mobile DNA II Edited by N.L., Craig et al. ASM Press 305-366
with permission of American Society of  Microbiology the 10-26-01.

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Last modification : December 19 2001