Escherichia coli K-12 substr. MG1655 Polypeptide: InsAB' transposase

Gene: insAB-1 Accession Number: G0-10535 (EcoCyc)

Regulation Summary Diagram: ?

Regulation summary diagram for insAB-1

IS1 is the smallest insertion sequence in E. coli. It codes for three proteins, InsA, InsB and InsAB'.

InsAB' is the transposase for IS1 [Escoubas94]. Its translation depends on a -1 frameshift within the 3' end region of insA which allows translational readthrough into insB [Sekine89]. In the absence of this frameshift, the IS1 transcriptional repressor protein InsA is produced instead [Sekine89, Escoubas94, Matsutani97].

InsAB' acts preferentially near the IS1 sequence, thus promoting stable existence of the IS1 element within the genome [Matsutani97]. Its transposition function requires the H-NS DNA-binding transcriptional dual regulator [Shiga01].

The structural basis of InsAB' function has been examined [Ohta04, TonHoang04].
Note that although this page mentions "Exons/Introns" and "Spliced Nucleotide Sequence", it actually describes ribosomal frameshifting.

Map Position: [19,811 <- 20,508] (0.43 centisomes, 2°)
Length: 698 bp / 232 aa

Molecular Weight of Polypeptide: 26.388 kD (from nucleotide sequence)

Unification Links: PortEco:insAB-1 , RegulonDB:G0-10535

GO Terms:

Biological Process: GO:0006313 - transposition, DNA-mediated Inferred from experiment [Escoubas94]
Molecular Function: GO:0004803 - transposase activity Inferred from experiment [Escoubas94]

MultiFun Terms: extrachromosomal transposon related

Last-Curated ? 29-Aug-2006 by Shearer A , SRI International

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram



Schematic showing introns, exons and/or isoforms of insAB-1

Ingrid Keseler on Wed Mar 7, 2012:
Gene end position corrected to be the same as that of insB-1.


Escoubas94: Escoubas JM, Lane D, Chandler M (1994). "Is the IS1 transposase, InsAB', the only IS1-encoded protein required for efficient transposition?." J Bacteriol 176(18);5864-7. PMID: 8083181

Matsutani97: Matsutani S (1997). "Genetic analyses of the interactions of the IS1-encoded proteins with the left end of IS1 and its insertion hotspot." J Mol Biol 267(3);548-60. PMID: 9126837

Ohta04: Ohta S, Yoshimura E, Ohtsubo E (2004). "Involvement of two domains with helix-turn-helix and zinc finger motifs in the binding of IS1 transposase to terminal inverted repeats." Mol Microbiol 53(1);193-202. PMID: 15225314

Sekine89: Sekine Y, Ohtsubo E (1989). "Frameshifting is required for production of the transposase encoded by insertion sequence 1." Proc Natl Acad Sci U S A 86(12);4609-13. PMID: 2543983

Shiga01: Shiga Y, Sekine Y, Kano Y, Ohtsubo E (2001). "Involvement of H-NS in transpositional recombination mediated by IS1." J Bacteriol 183(8);2476-84. PMID: 11274106

TonHoang04: Ton-Hoang B, Turlan C, Chandler M (2004). "Functional domains of the IS1 transposase: analysis in vivo and in vitro." Mol Microbiol 53(5);1529-43. PMID: 15387827

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Fri Oct 9, 2015, BIOCYC14B.