Bridge helix bending promotes RNA polymerase II backtracking through a critical and conserved threonine residue
KAUST DepartmentComputational Bioscience Research Center (CBRC)
Permanent link to this recordhttp://hdl.handle.net/10754/606053
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AbstractThe dynamics of the RNA polymerase II (Pol II) backtracking process is poorly understood. We built a Markov State Model from extensive molecular dynamics simulations to identify metastable intermediate states and the dynamics of backtracking at atomistic detail. Our results reveal that Pol II backtracking occurs in a stepwise mode where two intermediate states are involved. We find that the continuous bending motion of the Bridge helix (BH) serves as a critical checkpoint, using the highly conserved BH residue T831 as a sensing probe for the 3′-terminal base paring of RNA:DNA hybrid. If the base pair is mismatched, BH bending can promote the RNA 3′-end nucleotide into a frayed state that further leads to the backtracked state. These computational observations are validated by site-directed mutagenesis and transcript cleavage assays, and provide insights into the key factors that regulate the preferences of the backward translocation.
CitationBridge helix bending promotes RNA polymerase II backtracking through a critical and conserved threonine residue 2016, 7:11244 Nature Communications
SponsorsX.H. acknowledges the Hong Kong Research Grants Council (16302214, 609813, HKUST C6009-15G, AoE/M-09/12, T13-607/12R, and M-HKUST601/13) and National Science Foundation of China 21273188. D.W. acknowledges the NIH (GM102362), Kimmel Scholars award from the Sidney Kimmel Foundation for Cancer Research, start-up funds from Skaggs School of Pharmacy and Pharmaceutical Sciences, UCSD and Academic Senate Research Award from UCSD. X.G. was supported by funding from the King Abdullah University of Science and Technology. F.P. acknowledges the support from Hong Kong PhD Fellowship Scheme (2011/12) and the partial support for PhD studies from the CONACYT. This research made use of the resources of the Supercomputing Laboratory at King Abdullah University of Science and Technology. We thank Dr Jeffery Strathern (NCI) for providing yeast strain containing Pol II Rpb1 T831A mutant and Dr Mikhail Kashlev for providing purified Pol II Rpb1 T831A mutant.
- Dynamics of bridge helix bending in RNA polymerase II.
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- Issue date: 2017 Apr
- Millisecond dynamics of RNA polymerase II translocation at atomic resolution.
- Authors: Silva DA, Weiss DR, Pardo Avila F, Da LT, Levitt M, Wang D, Huang X
- Issue date: 2014 May 27
- Structural basis of RNA polymerase II backtracking, arrest and reactivation.
- Authors: Cheung AC, Cramer P
- Issue date: 2011 Mar 10
- Structural basis of transcription: backtracked RNA polymerase II at 3.4 angstrom resolution.
- Authors: Wang D, Bushnell DA, Huang X, Westover KD, Levitt M, Kornberg RD
- Issue date: 2009 May 29
- Structural basis of transcription: mismatch-specific fidelity mechanisms and paused RNA polymerase II with frayed RNA.
- Authors: Sydow JF, Brueckner F, Cheung AC, Damsma GE, Dengl S, Lehmann E, Vassylyev D, Cramer P
- Issue date: 2009 Jun 26