You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Multilevel autoregulation of λ repressor protein CI by DNA looping in vitro
Dale Lewis, Phuoc Le, Chiara Zurla, Laura Finzi and Sankar Adhya
Proceedings of the National Academy of Sciences of the United States of America
Vol. 108, No. 36 (September 6, 2011), pp. 14807-14812
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/27979383
Page Count: 6
You can always find the topics here!Topics: DNA, Repression, Dimers, Bacteriophage lambda, Genetic mutation, Gene expression regulation, Bacteriophages, Autoregulation, Genes, Genetics
Were these topics helpful?See something inaccurate? Let us know!
Select the topics that are inaccurate.
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Preview not available
The prophage state of bacteriophage λ is extremely stable and is maintained by a highly regulated level of λ repressor protein, CI, which represses lytic functions. CI regulates its own synthesis in a lysogen by activating and repressing its promoter, PRM. CI participates in long-range interactions involving two regions of widely separated operator sites by generating a loop in the intervening DNA. We investigated the roles of each individual site under conditions that permitted DNA loop formation by using in vitro transcription assays for the first time on supercoiled DNA that mimics in vivo situation. We confirmed that DNA loops generated by oligomerization of CI bound to its operators influence the autoactivation and autorepression of PRM regulation. We additionally report that different configurations of DNA loops are central to this regulation—one configuration further enhances autoactivation and another is essential for autorepression of PRM.
Proceedings of the National Academy of Sciences of the United States of America © 2011 National Academy of Sciences