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 Cocozaki, A. I.
Right arrow Articles by Smith, C. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cocozaki, A. I.
Right arrow Articles by Smith, C. A.

 Previous Article  |  Next Article 

Journal of Bacteriology, June 2008, p. 4263-4271, Vol. 190, No. 12
0021-9193/08/$08.00+0     doi:10.1128/JB.00059-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Bacteriophage P22 Antitermination boxB Sequence Requirements Are Complex and Overlap with Those of {lambda}{triangledown}

Alexis I. Cocozaki, Ingrid R. Ghattas, and Colin A. Smith*

Department of Biology, American University of Beirut, Beirut, Lebanon

Received 12 January 2008/ Accepted 10 April 2008

Transcription antitermination in phages {lambda} and P22 uses N proteins that bind to similar boxB RNA hairpins in regulated transcripts. In contrast to the {lambda} N-boxB interaction, the P22 N-boxB interaction has not been extensively studied. A nuclear magnetic resonance structure of the P22 N peptide boxBleft complex and limited mutagenesis have been reported but do not reveal a consensus sequence for boxB. We have used a plasmid-based antitermination system to screen boxBs with random loops and to test boxB mutants. We find that P22 N requires boxB to have a GNRA-like loop with no simple requirements on the remaining sequences in the loop or stem. U:A or A:U base pairs are strongly preferred adjacent to the loop and appear to modulate N binding in cooperation with the loop and distal stem. A few GNRA-like hexaloops have moderate activity. Some boxB mutants bind P22 and {lambda} N, indicating that the requirements imposed on boxB by P22 N overlap those imposed by {lambda} N. Point mutations can dramatically alter boxB specificity between P22 and {lambda} N. A boxB specific for P22 N can be mutated to {lambda} N specificity by a series of single mutations via a bifunctional intermediate, as predicted by neutral theories of evolution.

* Corresponding author. Mailing address: Department of Biology, American University of Beirut, P.O. Box 11-0236, Riad El Solh 1107 2020, Beirut, Lebanon. Phone: 961 3 791313, ext. 3887. Fax: 961 1 744 461. E-mail: cs10{at}aub.edu.lb

{triangledown} Published ahead of print on 18 April 2008.

Journal of Bacteriology, June 2008, p. 4263-4271, Vol. 190, No. 12
0021-9193/08/$08.00+0     doi:10.1128/JB.00059-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Cocozaki, A. I., Ghattas, I. R., Smith, C. A. (2008). The RNA-Binding Domain of Bacteriophage P22 N Protein Is Highly Mutable, and a Single Mutation Relaxes Specificity toward {lambda}. J. Bacteriol. 190: 7699-7708 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»