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A Genetic Network That Balances Two Outcomes Utilizes Asymmetric Recognition of Operator Sites

IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata

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Title A Genetic Network That Balances Two Outcomes Utilizes Asymmetric Recognition of Operator Sites
 
Creator Mazumder, Abhishek
Bandyopadhyay, Sumita
Dhar, Amlanjyoti
Lewis, Dale E. A
Deb, Sunanda
Dey, Sucharita
Chakrabarti, Pinak
Roy, Siddhartha
 
Subject Structural Biology & Bioinformatics
 
Description Stability and induction of the lysogenic state of bacteriophage l are balanced by a complex regulatory network. A key feature of this network is the mutually exclusive cooperative binding of a repressor dimer (CI) to one of two pairs of binding sites, OR1-OR2 or OR2-OR3. The structural features that underpin the mutually exclusive binding mode are not well understood. Recent studies have demonstrated that CI is an asymmetric dimer. The functional importance of the asymmetry is not fully clear. Due to the asymmetric nature of the CI dimer as well as its binding sites, there are two possible bound orientations. By fluorescence resonance energy transfer measurements we showed that CI prefers one bound orientation. We also demonstrated that the relative configuration of the binding sites is important for CI dimer-dimer interactions and consequent cooperative binding. We proposed that the operator configuration dictates the orientations of the bound CI molecules, which in turn dictates CI cooperative interaction between the OR1-OR2 or OR2-OR3, but not both. Modeling suggests that the relative orientation of the C- and N-terminal domains may play an important role in the mutually exclusive nature of the cooperative binding. This work correlates unique structural features of a transcription regulatory protein with the functional properties of a gene regulatory network.
 
Publisher Biophysical Society
 
Date 2012
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://www.eprints.iicb.res.in/1725/1/BIOPHYSICAL_JOURNAL__Volume_102___Issue_7___Pages_1580%2D1589_;2012[121].pdf
Mazumder, Abhishek and Bandyopadhyay, Sumita and Dhar, Amlanjyoti and Lewis, Dale E. A and Deb, Sunanda and Dey, Sucharita and Chakrabarti, Pinak and Roy, Siddhartha (2012) A Genetic Network That Balances Two Outcomes Utilizes Asymmetric Recognition of Operator Sites. Biophysical Journal, 102 (7). pp. 1580-1589. ISSN 0006-3495
 
Relation http://dx.doi.org/10.1016/j.bpj.2012.01.052
http://www.eprints.iicb.res.in/1725/