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Báo cáo y học: "Location of DNA damage by charge exchanging repair enzymes: effects of cooperativity on location time"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Location of DNA damage by charge exchanging repair enzymes: effects of cooperativity on location time | Theoretical Biology and Medical Modelling BioMed Central Research Open Access Location of DNA damage by charge exchanging repair enzymes effects of cooperativity on location time Kasper Astrup Eriksen Address Department of Theoretical Physics Lund University Sõlvegatan 14A SE-223 62 Lund Sweden Email Kasper Astrup Eriksen - kasper.eriksen@thep.lu.se Corresponding author Published 08 April 2005 Received 06 December 2004 Theoretical Biology and Medical Modelling 2005 2 15 doi 10.1186 1742-4682-2-15 Accepted 08 April 2005 This article is available from http www.tbiomed.cOm content 2 1 15 2005 Eriksen licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http creativecommons.org licenses by 2.0 which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background How DNA repair enzymes find the relatively rare sites of damage is not known in great detail. Recent experiments and molecular data suggest that individual repair enzymes do not work independently of each other but interact with each other through charges exchanged along the DNA. A damaged site in the DNA hinders this exchange. The hypothesis is that the charge exchange quickly liberates the repair enzymes from error-free stretches of DNA. In this way the sites of damage are located more quickly but how much more quickly is not known nor is it known whether the charge exchange mechanism has other observable consequences. Results Here the size of the speed-up gained from this charge exchange mechanism is calculated and the characteristic length and time scales are identified. In particular for Escherichia coli I estimate the speed-up is 50000 N where N is the number of repair enzymes participating in the charge exchange mechanism. Even though N is not exactly known a speed-up of order 10 is not entirely unreasonable. Furthermore upon over expression of all the .