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Single stranded DNA translocation of E. coli UvrD monomer is tightly coupled to ATP hydrolysis
dc.contributor.author | Tomko, Eric J. | |
dc.contributor.author | Fischer, Christopher J. | |
dc.contributor.author | Lohman, Timothy M. | |
dc.date.accessioned | 2017-03-27T21:05:41Z | |
dc.date.available | 2017-03-27T21:05:41Z | |
dc.date.issued | 2012-02-14 | |
dc.identifier.citation | Tomko, Eric J., Christopher J. Fischer, and Timothy M. Lohman. "Single-Stranded DNA Translocation of E. Coli UvrD Monomer Is Tightly Coupled to ATP Hydrolysis." Journal of Molecular Biology 418.1-2 (2012): 32-46. | en_US |
dc.identifier.uri | http://hdl.handle.net/1808/23492 | |
dc.description.abstract | E. coli UvrD is an SF1A helicase/translocase that functions in several DNA repair pathways. A UvrD monomer is a rapid and processive single-stranded (ss) DNA translocase, but is unable to unwind DNA processively in vitro. Based on data at saturating ATP (500 μM) we proposed a non-uniform stepping mechanism in which a UvrD monomer translocates with biased (3′ to 5′) directionality while hydrolyzing 1 ATP per DNA base translocated, but with a kinetic step-size of 4–5 nucleotides/step, suggesting a pause occurs every 4–5 nucleotides translocated. To further test this mechanism we examined UvrD translocation over a range of lower ATP concentrations (10–500 μM ATP), using transient kinetic approaches. We find a constant ATP coupling stoichiometry of ~1 ATP/DNA base translocated even at the lowest ATP concentration examined (10 μM) indicating that ATP hydrolysis is tightly coupled to forward translocation of a UvrD monomer along ssDNA with little slippage or futile ATP hydrolysis during translocation. The translocation kinetic step size remains constant at 4–5 nucleotides/step down to 50 μM ATP, but increases to ~7 nucleotides/step at 10 μM ATP. These results suggest that UvrD pauses more frequently during translocation at low ATP, but with little futile ATP hydrolysis. | en_US |
dc.publisher | Elsevier | en_US |
dc.rights | This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License 3.0 (CC BY-NC-ND 3.0 US), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. | en_US |
dc.subject | Helicase | en_US |
dc.subject | Motor protein | en_US |
dc.subject | Translocase | en_US |
dc.subject | Kinetic step size | en_US |
dc.subject | ATP coupling stoichiometry | en_US |
dc.title | Single stranded DNA translocation of E. coli UvrD monomer is tightly coupled to ATP hydrolysis | en_US |
dc.type | Article | en_US |
kusw.kuauthor | Fischer, Christopher J. | |
kusw.kudepartment | Physics and Astronomy | en_US |
dc.identifier.doi | 10.1016/j.jmb.2012.02.013 | en_US |
kusw.oaversion | Scholarly/refereed, author accepted manuscript | en_US |
kusw.oapolicy | This item meets KU Open Access policy criteria. | en_US |
dc.rights.accessrights | openAccess |