title: Induction of the SOS response in Escherichia coli inhibits Tn5 and IS50 transposition.
abstract: In response to DNA damage or the inhibition of normal DNA replication in Escherichia coli, a set of some 20 unlinked operons is induced through the RecA-mediated cleavage of the LexA repressor. We examined the effect of this SOS response on the transposition of Tn5 and determined that the frequency of transposition is reduced 5- to 10-fold in cells that constitutively express SOS functions, e.g., lexA(Def) strains. Furthermore, this inhibition is independent of recA function, is fully reversed by a wild-type copy of lexA, and is not caused by an alteration in the levels of the Tn5 transposase or inhibitor proteins. We isolated insertion mutations in a lexA(Def) background that reverse this transposition defect; all of these mapped to a new locus near 23 min on the E. coli chromosome.
authors.affiliation: Department of Biochemistry, University of Wisconsin, Madison 53706.
authors.forename: M D
authors.initials: MD
authors.lastname: Weinreich
authors.forename: J C
authors.initials: JC
authors.lastname: Makris
authors.forename: W S
authors.initials: WS
authors.lastname: Reznikoff
mesh_terms: D000483:Alleles; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000235:genetics*; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D011938:Rec A Recombinases / Q000378:metabolism; D013014:SOS Response, Genetics; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D011938:Rec A Recombinases; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein