Skip Navigation


Nucleic Acids Research Advance Access first published online on September 22, 2009
This version published online on September 30, 2009
Nucleic Acids Research, doi:10.1093/nar/gkp769
This Article
Right arrow Full Text Freely available
Right arrow Print PDF (1661K) Freely available
Right arrow Screen PDF (551K) Freely available
Right arrow Supplementary Data
Right arrowOA All Versions of this Article:
gkp769v2    most recent
gkp769v1
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 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 Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Wilson, G. W.
Right arrow Articles by Edgell, D. R.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wilson, G. W.
Right arrow Articles by Edgell, D. R.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author(s) 2009. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Genome Integrity, Repair and Replication

Phage T4 mobE promotes trans homing of the defunct homing endonuclease I-TevIII

Gavin W. Wilson and David R. Edgell*

Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, N6A 5C1, Canada

*To whom correspondence should be addressed. Tel: +1 519 661 3133; Fax: +1 519 661 3175; Email: dedgell{at}uwo.ca

Received July 24, 2009. Revised August 17, 2009. Accepted September 1, 2009.

Homing endonucleases are site-specific DNA endonucleases that typically function as mobile genetic elements by introducing a double-strand break (DSB) in genomes that lack the endonuclease, resulting in a unidirectional gene conversion event that mobilizes the homing endonuclease gene and flanking DNA. Here, we characterize phage T4-encoded mobE, a predicted free-standing HNH family homing endonuclease. We show that mobE is promoterless and dependent on upstream transcription for expression, and that an internal intrinsic terminator regulates mobE transcript levels. Crucially, in vivo mapping experiments revealed a MobE-dependent, strand-specific nick in the non-coding strand of the nrdB gene of phage T2. An internal deletion of the predicted HNH catalytic motif of MobE abolishes nicking, and reduces high-frequency inheritance of mobE. Sequence polymorphisms of progeny phage that inherit mobE are consistent with DSB repair pathways. Significantly, we found that mobility of the neighboring I-TevIII, a defunct homing endonuclease encoded within a group I intron interrupting the nrdB gene of phage T4, was dependent on an intact mobE gene. Thus, our data indicate that the stagnant nrdB intron and I-TevIII are mobilized in trans as a consequence of a MobE-dependent gene conversion event, facilitating persistence of genetic elements that have no inherent means of promoting their own mobility.


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




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.