HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Asano, K. Articles by Mizobuchi, K. Search for Related Content PubMed PubMed Citation Articles by Asano, K. Articles by Mizobuchi, K. Social Bookmarking                      What's this?

J Biol Chem, Vol. 273, Issue 19, 11815-11825, May 8, 1998

An RNA Pseudoknot as the Molecular Switch for Translation of the repZ Gene Encoding the Replication Initiator of IncI Plasmid ColIb-P9

Katsura Asano and Kiyoshi Mizobuchi^¶

From the  Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Hongo, Tokyo 113, Japan and the ^¶ Department of Applied Physics and Chemistry, University of Electro-Communications, Chofu-shi, Tokyo 182, Japan

Translation initiation of the repZ gene encoding the replication initiator of plasmid ColIb-P9 is not only negatively regulated by the action of the antisense Inc RNA encoded in the leader region, but is also coupled to the translation and termination of a transcribed leader sequence, repY, a positive regulatory element for repZ gene expression. This translational coupling depends on base pairing between two complementary sequences, 5'-rGGCG-3' and 5'-rCGCC-3', which are located upstream of and in the middle of repY, respectively, and have the potential to form a pseudoknot with the stem-loop structure I. Another stem-loop called structure III near the 3'-end of repY sequesters both the 5'-rCGCC-3' sequence and the repZ ribosome-binding site. Here we show that the RepZ mRNA leader sequence synthesized in vitro indeed contains several stem-loop structures including structures I and III, but not the pseudoknot. However, disruption of structure III, without changing the repZ ribosome-binding site, by means of base substitution and deletion induces base pairing between the two short complementary sequences distantly separated, resulting in the formation of a pseudoknot. When the pseudoknot is allowed to form in vivo due to the same mutations, a maximum level of repZ expression is obtained comparable to one observed in the absence of Inc RNA. These results strengthen our previously proposed model that the pseudoknot induced by the translation and termination of the repY reading frame functions as the molecular switch for translational initiation of the repZ gene.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				T. Betteridge, J. Yang, A. J. Pittard, and J. Praszkier Interaction of the Initiator Protein of an IncB Plasmid with Its Origin of DNA Replication J. Bacteriol., April 1, 2003; 185(7): 2210 - 2218. [Abstract] [Full Text] [PDF]

				J. Praszkier and A. J. Pittard Pseudoknot-Dependent Translational Coupling in repBA Genes of the IncB Plasmid pMU720 Involves Reinitiation J. Bacteriol., October 15, 2002; 184(20): 5772 - 5780. [Abstract] [Full Text] [PDF]

				C.-Y. Wu, J.-F. Fu, and S.-T. Liu The replicon of pSW800 from Pantoea stewartii Microbiology, October 1, 2001; 147(10): 2757 - 2767. [Abstract] [Full Text] [PDF]

				K. Asano and K. Mizobuchi Structural Analysis of Late Intermediate Complex Formed between Plasmid ColIb-P9 Inc RNA and Its Target RNA. HOW DOES A SINGLE ANTISENSE RNA REPRESS TRANSLATION OF TWO GENES AT DIFFERENT RATES? J. Biol. Chem., January 14, 2000; 275(2): 1269 - 1274. [Abstract] [Full Text] [PDF]

				K. Asano, C. Hama, S.-i. Inoue, H. Moriwaki, and K. Mizobuchi The Plasmid ColIb-P9 Antisense Inc RNA Controls Expression of the RepZ Replication Protein and Its Positive Regulator repY with Different Mechanisms J. Biol. Chem., June 18, 1999; 274(25): 17924 - 17933. [Abstract] [Full Text] [PDF]

				V. Athanasopoulos, J. Praszkier, and A. J. Pittard Analysis of Elements Involved in Pseudoknot-Dependent Expression and Regulation of the repA Gene of an IncL/M Plasmid J. Bacteriol., March 15, 1999; 181(6): 1811 - 1819. [Abstract] [Full Text]

				K. Asano, T. Niimi, S. Yokoyama, and K. Mizobuchi Structural Basis for Binding of the Plasmid ColIb-P9 Antisense Inc RNA to Its Target RNA with the 5'-rUUGGCG-3' Motif in the Loop Sequence J. Biol. Chem., May 8, 1998; 273(19): 11826 - 11838. [Abstract] [Full Text] [PDF]