Imperial College London
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Professor Ramesh Wigneshweraraj

Faculty of Medicine, Department of Infectious Disease

Professor of Molecular Microbiology
 
 
 
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Contact

 

+44 (0)20 7594 1867s.r.wig

 
 
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Location

 

4.40BFlowers buildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Duchi:2017:nar/gkx1146,
author = {Duchi, D and Gryte, K and Robb, NC and Morichaud, Z and Sheppard, C and Brodolin, K and Wigneshweraraj, S and Kapanidis, AN},
doi = {nar/gkx1146},
journal = {Nucleic Acids Research},
pages = {677--688},
title = {Conformational heterogeneity and bubble dynamics in single bacterial transcription initiation complexes.},
url = {http://dx.doi.org/10.1093/nar/gkx1146},
volume = {46},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Transcription initiation is a major step in gene regulation for all organisms. In bacteria, the promoter DNA is first recognized by RNA polymerase (RNAP) to yield an initial closed complex. This complex subsequently undergoes conformational changes resulting in DNA strand separation to form a transcription bubble and an RNAP-promoter open complex; however, the series and sequence of conformational changes, and the factors that influence them are unclear. To address the conformational landscape and transitions in transcription initiation, we applied single-molecule Förster resonance energy transfer (smFRET) on immobilized Escherichia coli transcription open complexes. Our results revealed the existence of two stable states within RNAP-DNA complexes in which the promoter DNA appears to adopt closed and partially open conformations, and we observed large-scale transitions in which the transcription bubble fluctuated between open and closed states; these transitions, which occur roughly on the 0.1 s timescale, are distinct from the millisecond-timescale dynamics previously observed within diffusing open complexes. Mutational studies indicated that the σ70 region 3.2 of the RNAP significantly affected the bubble dynamics. Our results have implications for many steps of transcription initiation, and support a bend-load-open model for the sequence of transitions leading to bubble opening during open complex formation.
AU  - Duchi,D
AU  - Gryte,K
AU  - Robb,NC
AU  - Morichaud,Z
AU  - Sheppard,C
AU  - Brodolin,K
AU  - Wigneshweraraj,S
AU  - Kapanidis,AN
DO  - nar/gkx1146
EP  - 688
PY  - 2017///
SN  - 0305-1048
SP  - 677
TI  - Conformational heterogeneity and bubble dynamics in single bacterial transcription initiation complexes.
T2  - Nucleic Acids Research
UR  - http://dx.doi.org/10.1093/nar/gkx1146
UR  - http://hdl.handle.net/10044/1/56575
VL  - 46
ER  -
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