IS2

Description:

IS2 is a 1331 bp transposable insertion sequence.
IS2 contains two open reading frames, insC and insD, involved in transposase function.

Details:

IS2 can generate a 5 bp target site duplication, but some insertions have no apparent target site duplications.

IS2 has an outward directed promoter at its end that can be utilized to activate transcription from silent genes, for example an IS2 insertion at -515 relative to the oppA translation start in strain MA261 introduces the strong promoter which is at the end of IS2; which initiates transcription is initiated three nucleotides past the end of IS2, creating a 511 nt 5' UTR in that strain; the parent strain W3110 does not have an IS2 insertion at oppA (Igarashi, 1997).

E. coli K-12 strain MG1655 contains seven instances of IS2.


'
IS2 Left End Right End Ori Length Comments
IS2A 381260 382590 (+) 1331 5 bp target site duplication ATTAC interrupts yaiX'
IS2D 1467910 1469240 (-) 1331 5 bp target site duplication AACCC, interrupts ydbA'
IS2E' 1650843 1651548 (+) 706 IS2E' is a partial IS2 sequence missing insC5 and codons 1-71 of insD5'; IS2E' interrupts and truncates ydfE' and intQ'
IS2F 2068941 2070271 (-) 13315 bp target site duplication GTGGC; yoeA' and yeeP' 200 bp past IS2F
IS2H 2996361 2997691 (-) 1331 no target site duplication; interrupts and truncates ygeO' and ygeQ'
IS2I 3186096 3187426 (+) 1331 5 bp target site duplication GTTAT, interrupts yqiG'
IS2K 4498181 4499511 (+) 1331 5 bp target site duplication CCTTG

IS2B, IS2C, and IS2G are noted as insertion points at positions 1105381, 1299461, and 2317459, respectively, because these are not present in MG1655 but are present in E. coli K-12 strain W3110.