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 Google Scholar
Google Scholar
Right arrow Articles by Dabrazhynetskaya, A.
Right arrow Articles by Austin, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dabrazhynetskaya, A.
Right arrow Articles by Austin, S.

 Previous Article  |  Next Article 

Journal of Bacteriology, February 2009, p. 1126-1131, Vol. 191, No. 4
0021-9193/09/$08.00+0     doi:10.1128/JB.01358-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Switching Protein-DNA Recognition Specificity by Single-Amino-Acid Substitutions in the P1 par Family of Plasmid Partition Elements{triangledown}

Alena Dabrazhynetskaya,1 Therese Brendler,1 Xinhua Ji,2 and Stuart Austin1*

Gene Regulation and Chromosome Biology Laboratory,1 Macromolecular Crystallography Laboratory, National Cancer Institute, CCR, NCI—Frederick, Frederick, Maryland 21702-12012

Received 29 September 2008/ Accepted 7 November 2008

The P1, P7, and pMT1 par systems are members of the P1 par family of plasmid partition elements. Each has a ParA ATPase and a ParB protein that recognizes the parS partition site of its own plasmid type to promote the active segregation of the plasmid DNA to daughter cells. ParB contacts two parS motifs known as BoxA and BoxB, the latter of which determines species specificity. We found that the substitution of a single orthologous amino acid in ParB for that of a different species has major effects on the specificity of recognition. A single change in ParB can cause a complete switch in recognition specificity to that of another species or can abolish specificity. Specificity changes do not necessarily correlate with changes in the gross DNA binding properties of the protein. Molecular modeling suggests that species specificity is determined by the capacity to form a hydrogen bond between ParB residue 288 and the second base in the BoxB sequence. As changes in just one ParB residue and one BoxB base can alter species specificity, plasmids may use such simple changes to evolve new species rapidly.

* Corresponding author. Mailing address: Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute, CCR, NCI—Frederick, Frederick, MD 21702-1201. Phone: (301) 846-1266. Fax: (301) 846-6988. E-mail: austin{at}ncifcrf.gov

{triangledown} Published ahead of print on 21 November 2008.

Journal of Bacteriology, February 2009, p. 1126-1131, Vol. 191, No. 4
0021-9193/09/$08.00+0     doi:10.1128/JB.01358-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





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