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 1090448
278 <5/20(수) 오후4:30분> Nonequilibrium statistical physics for Brownian heat engine 2015.05.14 63379
277 <5/16(토)> 세미나 개최 안내 2015.05.18 228133
276 <5/27(수) 오후4:30분>Controlling phases in epitaxial transition metal oxide thin films 2015.05.21 116854
275 <5/26(화)> 세미나 개최 안내 2015.05.27 64505
274 <6/3(수) 오후4:30분> The Quest for Dark Matter: Discovering Its Nature Underground? 2015.05.28 75794
273 <6/2(화)> 세미나 개최 안내 2015.06.01 62625
272 <6/10(수) 오후4:30분> Closing in on the Axion Dark Matter hypothesis 2015.06.03 75336
271 <6/9(화)> 세미나 개최 안내 2015.06.09 70070
270 2015학년도 2학기 콜로퀴움 일정 2015.08.06 90599
269 <8/29(토)> 세미나 개최 안내 2015.09.01 70011
268 <Sep. 9(Wed.) 4:30 PM> Electronic structures of strongly-correlated systems 2015.09.03 93978
267 <Sep. 16(Wed.) 4:30 PM> Watching molecular targets in living bodies: the cutting edge in clinical medicine 2015.09.09 74664
266 <Sep. 18(Fri.) 4:00 PM> Special seminar 2015.09.16 59361
265 <Sep. 23(Wed.) 4:30 PM>Grain boundary effect in Metal : A journey of discovery from crystal to thin films without grain boundaries 2015.09.16 218269
264 <Sep. 30(Wed.) 4:30 PM>Local electronic structures of stacking grain boundary in bilayer graphene 2015.09.23 96642
263 학술세미나 개최 안내: Local Modes in Vibrational (and Rotational) Spectroscopy file 2015.10.01 56685
262 <Oct. 7(Wed.) 4:30 PM> Observing Ultra High Energy Cosmic Rays with your Smartphone 2015.10.02 201727
261 <Oct. 20(Tue.) 2:00 PM> High-throughput Synthesis of Oxide Thin Films 2015.10.05 150842
260 <Oct. 14(Wed.) 4:30 PM> 국방과학기술과 물리학 2015.10.07 66774
» <Oct.15(Thu) 16:30> Single-Molecule Approach to Homology Search & Strand Exchange in Homologous Recombination 2015.10.12 127106