Authors
Chu, Stephanie W.Noyes, Marcus Blaine
Christensen, Ryan G.
Pierce, Brian G.
Zhu, Lihua Julie
Weng, Zhiping
Stormo, Gary D.
Wolfe, Scot A.
UMass Chan Affiliations
Program in Molecular MedicineProgram in Bioinformatics and Integrative Biology
Department of Biochemistry and Molecular Pharmacology
Program in Gene Function and Expression
Document Type
Journal ArticlePublication Date
2012-04-26
Metadata
Show full item recordAbstract
The recognition potential of most families of DNA-binding domains (DBDs) remains relatively unexplored. Homeodomains (HDs), like many other families of DBDs, display limited diversity in their preferred recognition sequences. To explore the recognition potential of HDs, we utilized a bacterial selection system to isolate HD variants from a randomized library that are compatible with each of the 64 possible 3' triplet sites (i.e. TAANNN). The majority of these selections yielded sets of HDs with overrepresented residues at specific recognition positions, implying the selection of specific binders. The DNA-binding specificity of 151 representative HD variants was subsequently characterized, identifying HDs that preferentially recognize 44 of these target sites. Many of these variants contain novel combinations of specificity determinants that are uncommon or absent in extant HDs. These novel determinants, when grafted into different HD backbones, produce a corresponding alteration in specificity. This information was used to create more explicit HD recognition models, which can inform the prediction of transcriptional regulatory networks for extant HDs or the engineering of HDs with novel DNA-recognition potential. The diversity of recovered HD recognition sequences raises important questions about the fitness barrier that restricts the evolution of alternate recognition modalities in natural systems.Source
Genome Res. 2012 Apr 26. [Epub ahead of print] doi 10.1101/gr.139014.112DOI
10.1101/gr.139014.112Permanent Link to this Item
http://hdl.handle.net/20.500.14038/43977PubMed ID
22539651Related Resources
Link to article in PubMedae974a485f413a2113503eed53cd6c53
10.1101/gr.139014.112