Multiple roles for TnpI recombinase in regulation of Tn5401 transposition in Bacillus thuringiensis

• Published in: Journal of Bacteriology Vol. 181; no. 20; pp. 6271 - 6277
• Main Authors: Baum, J.A, Gilmer, A.J, Mettus, A.M.L
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.10.1999
• Subjects: Bacillus thuringiensis; Bacillus thuringiensis - genetics; Bacillus thuringiensis - metabolism; Base Sequence; binding; Conjugation, Genetic; DNA Nucleotidyltransferases; DNA Nucleotidyltransferases - metabolism; DNA Transposable Elements; enzyme activity; gene expression; Gene Expression Regulation, Bacterial; genes; genetics; metabolism; Molecular Sequence Data; Mutation; nucleases; nucleotide sequences; Plasmids and Transposons; promoter regions; Protein Binding; recombinase; Recombinases; Recombination, Genetic; repetitive sequences; Repressor Proteins; Repressor Proteins - metabolism; terminal inverted repeats; tnpA gene; TnpA protein; tnpI gene; TnpI protein; Transposases; Transposases - metabolism; transposition; Transposon Resolvases; transposon Tn5401; transposons
• ISSN: 0021-9193; 1098-5530; 1067-8832
• DOI: 10.1128/JB.181.20.6271-6277.1999

Tn5401 is a class II transposable element derived from the gram-positive bacterium Bacillus thuringiensis. The 4,837-bp transposon encodes a Tn3-like transposase (TnpA) and an integrase-like recombinase (TnpI) and is notable for its unusually long 53-bp terminal inverted repeats (TIRs). The tnpA and tnpI genes are transcribed from a common promoter, designated P(R), that is subject to negative regulation by TnpI. The TIRs of Tn5401 each contain a 38-bp sequence that can be aligned with the 38- to 40-bp TIR sequences of Tn3-like transposons and an adjacent 12-bp sequence that binds TnpI. This unique juxtaposition of TnpA and TnpI binding sites suggests that TnpI may regulate the binding or catalytic activity of TnpA. The results of the present study indicate that TnpI, in addition to functioning as a site-specific recombinase and as a transcriptional repressor, is required for TnpA binding to the TIRs of Tn5401.