JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hõrak, R.
Right arrow Articles by Kivisaar, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hõrak, R.
Right arrow Articles by Kivisaar, M.

J Bacteriol, June 1998, p. 2822-2829, Vol. 180, No. 11
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Expression of the Transposase Gene tnpA of Tn4652 Is Positively Affected by Integration Host Factor

Rita Hõrak* and Maia Kivisaar

Estonian Biocentre and Institute of Molecular and Cell Biology, Tartu University, EE2400 Tartu, Estonia

Received 17 December 1997/Accepted 29 March 1998

Tn4652 is a derivative of the toluene degradation transposon Tn4651 that belongs to the Tn3 family of transposons (M. Tsuda and T. Iino, Mol. Gen. Genet. 210:270-276, 1987). We have sequenced the transposase gene tnpA of transposon Tn4652 and mapped its promoter to the right end of the element. The deduced amino acid sequence of tnpA revealed 96.2% identity with the putative transposase of Tn5041. Homology with other Tn3 family transposases was only moderate (about 20 to 24% identity), suggesting that Tn4652 and Tn5041 are distantly related members of the Tn3 family. Functional analysis of the tnpA promoter revealed that it is active in Pseudomonas putida but silent in Escherichia coli, indicating that some P. putida-specific factor is required for the transcription from this promoter. Additionally, tnpA promoter activity was shown to be modulated by integration host factor (IHF). The presence of an IHF-binding site upstream of the tnpA promoter enhanced the promoter activity. The positive role of IHF was also confirmed by the finding that the enhancing effect of IHF was not detected in the P. putida ihfA-deficient strain A8759. Moreover, the Tn4652 terminal sequences had a negative effect on transcription from the tnpA promoter in the ihfA-defective strain. This finding suggests that IHF not only enhances transcription from the tnpA promoter but also alleviates the negative effect of terminal sequences of Tn4652 on the promoter activity. Also, an in vitro binding assay demonstrated that both ends of Tn4652 bind IHF from a cell lysate of E. coli.

* Corresponding author. Mailing address: Estonian Biocentre and Institute of Molecular and Cell Biology, Tartu University, 23 Riia Str., EE2400 Tartu, Estonia. Phone: 372-7-465015. Fax: 372-7-420286. E-mail: rhorak{at}ebc.ee.

J Bacteriol, June 1998, p. 2822-2829, Vol. 180, No. 11
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1998 by the American Society for Microbiology. All rights reserved.