tailieunhanh - Báo cáo y học: "The design of transcription-factor binding sites is affected by combinatorial regulation"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: The design of transcription-factor binding sites is affected by combinatorial regulation. | Open Access Research The design of transcription-factor binding sites is affected by combinatorial regulation Yonatan Bilu and Naama Barkai Addresses Department of Molecular Genetics Weizmann Institute of Science 76100 Rehovot Israel. ỶDepartment of Physics of Complex Systems Weizmann Institute of Science 76100 Rehovot Israel. Correspondence Naama Barkai. E-mail Barkai@ Published 2 December 2005 Genome Biology 2005 6 R103 doi gb-2005-6-12-r103 The electronic version of this article is the complete one and can be found online at http 2005 6 12 R103 Received 10 May 2005 Revised 20 July 2005 Accepted 8 November 2005 2005 Bilu and Barkai licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Background Transcription factors regulate gene expression by binding to specific c s-regulatory elements in gene promoters. Although DNA sequences that serve as transcription-factor binding sites have been characterized and associated with the regulation of numerous genes the principles that govern the design and evolution of such sites are poorly understood. Results Using the comprehensive mapping of binding-site locations available in Saccharomyces cerev s ae we examined possible factors that may have an impact on binding-site design. We found that binding sites tend to be shorter and fuzzier when they appear in promoter regions that bind multiple transcription factors. We further found that essential genes bind relatively fewer transcription factors as do divergent promoters. We provide evidence that novel binding sites tend to appear in specific promoters that are already associated with multiple sites. Conclusion Two principal models may account for the observed correlations. First it may be .