Abstract
We study genetic switches formed from pairs of mutually repressing operons. The switch stability is characterized by a well-defined lifetime, which grows very rapidly, albeit subexponentially, with the number of copies of the most-expressed transcription factor. The switch stability can be drastically enhanced by overlapping the upstream regulatory domains such that competing regulatory molecules mutually exclude each other. Our results suggest that robustness against biochemical noise can provide a selection pressure that drives operons together in the course of evolution.
- Received 4 November 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.128101
©2004 American Physical Society