korean english


Home > 게시판 > 세미나

○ Date : 2015 10 15() 오후 4:30 ~ 5:30
○ Place : 
삼성학술도서관 7
Creative Learning Room
○ Speaker : Dr. Ja Yil Lee
이자일 박사 (콜럼비아 대학교, 미국
○ Topic : Single-Molecule Approach to Homology Search & Strand Exchange in Homologous Recombination


Homologous recombination (HR) is an important biological phenomenon because it repairs DNA double-strand break in an error-free way and rearranges genetic information during meiosis promoting genetic diversity. HR is mediated by the Rad51/RecA family of recombinases. The essential roles of the recombinases are searching for the homologous sequence and then exchanging DNA strands. Despite decades of work, the physical basis of the homology search and strand-exchange is not well-defined. Using the single-molecule DNA curtain technique, we find that 8-nt is the minimum size to search for homologous sequences and that the search process is accelerated by the facilitated exchange mechanism meaning by competitor-dependent dissociation. We also reveal that the strand exchange occurs in precise 3-nucleotide (nt) steps for prokaryotic RecA and eukaryotic Rad51 and Dmc1. The free energy difference between the steps is ~0.3 kBT, which is also conserved from bacteria to human. Molecular dynamics simulation suggests that Watson-Crick basepairing of base triplets is the molecular basis of the triplet stepping. Furthermore we show that all the recombinases can step over mismatched bases in the strand exchange. But only the meiosis-specific recombinase Dmc1 can step over mismatched bases without any destabilization of base-triplets, which enhances more genetic exchange during meiosis.

번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1015342
222 <4/5(Wed.) 11:00am>Adhesion forces between nanoparticles in gas-phase processes and application 2017.04.03 85144
221 <11/11> Revealing magnetism of nanoislands with quantitative insights into spin-polarized scanning tunneling spectroscopy 2013.11.05 85226
220 <10/10>Self-reconfigurable robots 2008.10.07 85327
219 <5/8>Recent trend of thin film battery 2009.05.06 85370
218 <8/17> Is Quantum Criticality a Key to Unconventional Superconductivity? 2006.08.09 85410
217 <3/16> Inelastic X-ray Scattering: past, present, and the future 2011.03.10 85447
216 <4/2> Supersymmetric vacua of mass-deformed M2-brane theory 2010.03.29 85506
215 <June 10(Thu.)>Oxide electronics utilizing spin-orbit coupling 2021.05.31 85512
214 <3/26> Shedding infrared light on high-Tc superconductors 2014.03.19 85601
213 <4/3>Enhanced emission rate from a single quantum well using surface plasmon 2009.03.31 85663
212 2011학년도 2학기 콜로퀴움 일정 안내 2011.08.22 85923
211 <5/12> An Infrared View of the Universe 2006.05.09 85998
210 <4/16>같은 곳을 바라보는 다른 시선 2010.04.09 86102
209 <1/14>Dark Matter signals from PAMELA and ATIC 2009.01.12 86116
208 <11/4>Plasmonic Properites of Metallic Nanostructures 2009.10.30 86152
207 <12/7>유럽입자물리연구소에서의 CMS 실험 2007.12.03 86229
206 2007학년도 2학기 콜로키엄 schedule 안내 2007.09.27 86411
205 <6/19> 초전도 특별세미나 2012.06.11 86548
204 <10/9> Smearing effect of membrane in plane-wave matrix model 2009.10.05 86555
203 <11/20> Particle Accelerators: Driving Forces for Energy 2009.11.16 86595