Translocation by T7 RNA polymerase: a sensitively poised Brownian ratchet

Journal of Molecular Biology
Qing Guo, Rui Sousa

Abstract

Studies of halted T7 RNA polymerase (T7RNAP) elongation complexes (ECs) or of T7RNAP transcription against roadblocks due to DNA-bound proteins indicate that T7RNAP translocates via a passive Brownian ratchet mechanism. Crystal structures of T7RNAP ECs suggest that translocation involves an active power-stroke. However, neither solution studies of halted or slowed T7RNAP ECs, nor crystal structures of static complexes, are necessarily relevant to how T7RNAP translocates during rapid elongation. A recent single molecule study of actively elongating T7RNAPs provides support for the Brownian ratchet mechanism. Here, we obtain additional evidence for the existence of a Brownian ratchet during active T7RNAP elongation by showing that both rapidly elongating and halted complexes are equally sensitive to pyrophosphate. Using chemical nucleases tethered to the polymerase we achieve sub-ångström resolution in measuring the average position of halted T7RNAP ECs and find that the positional equilibrium of the EC is sensitively poised between pre-translocated and post-translocated states. This may be important in maximizing the sensitivity of the polymerase to sequences that cause pausing or termination. We also confirm that a crystallogra...Continue Reading

References

Jan 10, 1997·Journal of Molecular Biology·R Guajardo, R Sousa
Mar 4, 1997·Proceedings of the National Academy of Sciences of the United States of America·N Komissarova, M Kashlev
Jun 22, 2000·Proceedings of the National Academy of Sciences of the United States of America·I Artsimovitch, R Landick
Oct 14, 2000·Journal of Molecular Biology·J Huang, R Sousa
Nov 8, 2002·Nature·Tahir H TahirovShigeyuki Yokoyama
Nov 4, 2004·Journal of Molecular Biology·Lu BaiMichelle D Wang
Feb 1, 2005·Cell·Rui Sousa
Feb 1, 2005·Cell·Gil Bar-NahumEvgeny Nudler
May 21, 2005·Physical Review Letters·Philippe ThomenFrançois Heslot
Nov 15, 2005·Nature·Elio A AbbondanzieriSteven M Block
Dec 20, 2005·Cell·Dmitry G Vassylyev, Irina Artsimovitch

❮ Previous
Next ❯

Citations

Dec 17, 2009·The Journal of Biological Chemistry·Swaroopa Paratkar, Smita S Patel
Jan 12, 2012·The Journal of Biological Chemistry·Toshiaki NakanoHiroshi Ide
Jan 26, 2010·Biochimica Et Biophysica Acta·Maria KireevaZachary F Burton
Aug 29, 2009·Proteins·Michael Feig, Zachary F Burton
Feb 23, 2012·Biochimica Et Biophysica Acta·Aishwarya P Deshpande, Smita S Patel
Oct 9, 2009·Current Opinion in Structural Biology·Thomas A Steitz
May 4, 2012·Biochimica Et Biophysica Acta·Jamie J ArnoldCraig E Cameron
Mar 21, 2008·Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics·Tripti Tripathi, Debashish Chowdhury
Mar 21, 2008·Physical Review Letters·Ravindra Venkatramani, Ravi Radhakrishnan
Sep 29, 2006·The Journal of Biological Chemistry·Vasanti Subramanian Anand, Smita S Patel
Nov 1, 2006·Biochemical Society Transactions·R Landick
Mar 16, 2007·Physical Review Letters·Lu BaiMichelle D Wang
Aug 16, 2006·Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics·Hyung-June Woo

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.