Skip Navigation

This Article
Right arrow Full Text Freely available
Right arrow Print PDF (183K) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Right arrow Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Zhang, X.
Right arrow Articles by Meyer, R. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, X.
Right arrow Articles by Meyer, R. J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Nucleic Acids Research, 2003, Vol. 31, No. 16 4762-4768
© 2003 Oxford University Press

Molecular handcuffing of the relaxosome at the origin of conjugative transfer of the plasmid R1162

Xiaolin Zhang, Shuyu Zhang1 and Richard J. Meyer*

Section of Molecular Genetics and Microbiology and The Institute for Molecular Biology, School of Biology, University of Texas at Austin, Austin, TX 78712, USA and 1 Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA

*To whom correspondence should be addressed. Tel: +1 512 471 3817; Fax: +1 512 471 7088; Email: rmeyer{at}mail.utexas.edu

The assembly of plasmid-encoded proteins at a unique site (oriT) on the plasmid R1162, to form a complex called the relaxosome, is required for conjugative transfer of the plasmid and for negative regulation of neighboring promoters. Two-dimensional chloroquine gel electrophoresis was used to show that oriTs are physically coupled at the relaxosome. This interaction requires all the relaxosome proteins, which are assembled into a structure resulting in a decrease in the average linking number of the plasmid DNA in the cell. Molecules with higher superhelical densities are preferentially selected for assembly of the relaxosome. Genetic data obtained earlier indicate that the molecular coupling reported here is a ‘handcuffing’ reaction that contributes to the regulation of adjacent plasmid promoters. However, although these promoters affect the expression of the genes for replication, plasmid copy-control is regulated independently. This is the first time ‘handcuffing’ has been observed at an oriT, and its possible significance for transfer is discussed.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Bacteriol.Home page
J. A. Caryl, M. C. A. Smith, and C. D. Thomas
Reconstitution of a Staphylococcal Plasmid-Protein Relaxation Complex In Vitro
J. Bacteriol., June 1, 2004; 186(11): 3374 - 3383.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.