title: ISDra2 transposition in Deinococcus radiodurans is downregulated by TnpB.
abstract: Transposable elements belonging to the recently identified IS200/IS605 family radically differ from classical insertion sequences in their transposition mechanism by strictly requiring single-stranded DNA substrates. This IS family includes elements encoding only the transposase (TnpA), and others, like ISDra2 from Deinococcus radiodurans, which contain a second gene, tnpB, dispensable for transposition and of unknown function to date. Here, we show that TnpB has an inhibitory effect on the excision and insertion steps of ISDra2 transposition. This inhibitory action of TnpB was maintained when ISDra2 transposition was induced by γ-irradiation of the host cells and required the integrity of its putative zinc finger motif. We also demonstrate the negative role of TnpB when ISDra2 transposition was monitored in a heterologous Escherichia coli host, indicating that TnpB-mediated inhibition does not involve Deinococcus-specific factors. TnpB therefore appears to play a regulatory role in ISDra2 transposition.
authors: University Paris-Sud, Institut de Génétique et Microbiologie (Bât. 409), UMR 8621, Orsay F-91405, France.
authors: Cécile
authors: C
authors: Pasternak
authors: Rémi
authors: R
authors: Dulermo
authors: Bao
authors: B
authors: Ton-Hoang
authors: Robert
authors: R
authors: Debuchy
authors: Patricia
authors: P
authors: Siguier
authors: Geneviève
authors: G
authors: Coste
authors: Michael
authors: M
authors: Chandler
authors: Suzanne
authors: S
authors: Sommer
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004251:DNA Transposable Elements / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D034301:Deinococcus / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects*; D015536:Down-Regulation; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D016254:Mutagenesis, Insertional; D019895:Transposases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D019895:Transposases