Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Initial Transcription by RNA Polymerase Proceeds Through a DNA-Scrunching Mechanism
Achillefs N. Kapanidis,1,2Emmanuel Margeat,1*Sam On Ho,1Ekaterine Kortkhonjia,1,3Shimon Weiss,1Richard H. Ebright3
Using fluorescence resonance energy transfer to monitor distanceswithin single molecules of abortively initiating transcriptioninitiation complexes, we show that initial transcription proceedsthrough a "scrunching" mechanism, in which RNA polymerase (RNAP)remains fixed on promoter DNA and pulls downstream DNA intoitself and past its active center. We show further that putativealternative mechanisms for RNAP active-center translocationin initial transcription, involving "transient excursions" ofRNAP relative to DNA or "inchworming" of RNAP relative to DNA,do not occur. The results support a model in which a stressedintermediate, with DNA-unwinding stress and DNA-compaction stress,is formed during initial transcription, and in which accumulatedstress is used to drive breakage of interactions between RNAPand promoter DNA and between RNAP and initiation factors duringpromoter escape.
1 Department of Chemistry and Biochemistry and Department of Physiology, University of California, Los Angeles, CA 90095, USA. 2 Clarendon Laboratory, Department of Physics, and IRC in Bionanotechnology, University of Oxford, Oxford OX1 3PU, UK. 3 Howard Hughes Medical Institute, Department of Chemistry, and Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA.
* Present address: Centre de Biochimie Structurale. CNRS UMR 5048.INSERM UMR 554. Université Montpellier I, 29 rue de Navacelles,34090 Montpellier cedex, France.
To whom correspondence should be addressed. E-mail: a.kapanidis1{at}physics.ox.ac.uk, sweiss{at}chem.ucla.edu, ebright{at}waksman.rutgers.edu
Sensor I Threonine of the AAA+ ATPase Transcriptional Activator PspF Is Involved in Coupling Nucleotide Triphosphate Hydrolysis to the Restructuring of {sigma}54-RNA Polymerase.
J. Schumacher, N. Joly, M. Rappas, D. Bradley, S. R. Wigneshweraraj, X. Zhang, and M. Buck (2007)
J. Biol. Chem.
282, 9825-9833
|Abstract »|Full Text »|PDF »
Abortive Initiation and Productive Initiation by RNA Polymerase Involve DNA Scrunching..
A. Revyakin, C. Liu, R. H. Ebright, and T. R. Strick (2006)
Science
314, 1139-1143
|Abstract »|Full Text »|PDF »
To whom correspondence should be addressed. E-mail: 
