This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Praszkier, J. Articles by Pittard, A. J. Search for Related Content PubMed PubMed Citation Articles by Praszkier, J. Articles by Pittard, A. J.

 Previous Article  |  Next Article 

Journal of Bacteriology, October 2002, p. 5772-5780, Vol. 184, No. 20
0021-9193/02/$04.00+0     DOI: 10.1128/JB.184.20.5772-5780.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Pseudoknot-Dependent Translational Coupling in repBA Genes of the IncB Plasmid pMU720 Involves Reinitiation

Department of Microbiology and Immunology, The University of Melbourne, Victoria 3010, Australia

Received 14 May 2002/ Accepted 19 July 2002

Replication of the IncB miniplasmid pMU720 requires synthesis of the replication initiator protein, RepA, whose translation is coupled to that of a leader peptide, RepB. The unusual feature of this system is that translational coupling in repBA has to be activated by the formation of a pseudoknot immediately upstream of the repA Shine-Dalgarno sequence. A small antisense RNA, RNAI, controls replication of pMU720 by interacting with repBA mRNA to inhibit expression of repA both directly, by preventing formation of the pseudoknot, and indirectly, by inhibiting translation of repB. The mechanism of translational coupling in repBA was investigated using the specialized ribosome system, which directs a subpopulation of ribosomes that carry an altered anti-Shine-Dalgarno sequence to translate mRNA molecules whose Shine-Dalgarno sequences have been altered to be complementary to the mutant anti-Shine-Dalgarno sequence. Our data indicate that translation of repA involves reinitiation by the ribosome that has terminated translation of repB. The role of the pseudoknot in this process and its effect on the control of copy number in pMU720 are discussed.

This article has been cited by other articles:

• Skorski, P., Leroy, P., Fayet, O., Dreyfus, M., Hermann-Le Denmat, S. (2006). The Highly Efficient Translation Initiation Region from the Escherichia coli rpsA Gene Lacks a Shine-Dalgarno Element.. J. Bacteriol. 188: 6277-6285 [Abstract] [Full Text]