logo

korean english

게시판

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



Abstract:

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 1060006
202 <4/30> Physical principles and applications of ultrasound in diagnostics and therapy 2014.04.22 69438
201 <6/5> 물리학도가 증권가로 간 까닭은... 2013.05.29 69418
200 <11/5> Optical spectroscopic probe on the surface state in three dimensional topological insulators 2012.10.24 69380
199 <12/30> Correlation between Raman scattering and conductance in a molecular junction 2013.12.23 69251
198 <3/20> 빛 : 우주의 신비를 푸는 열쇠 2013.03.14 69206
197 <6/15(Fri.) ~ 16(Sat.)> Formation of first star and galaxy, Gravitational waves from Binary Mergers of Sub-Solar Mass Dark Black Holes 2018.06.12 68782
196 <March. 30(Wed.) 4:30 PM> Tetraneutron (four-neutron nucleus) 2016.03.24 68752
195 <9/7(금)> Kondo Effect in Chiral Orbital Bands 2012.08.31 68327
194 <5/22> Vortex partition function and 3d dualities 2012.05.21 68316
193 <10/11(Tue.) 15:00>Analysis of Individual Terrestrial Gamma-ray Flashes 2016.10.10 68264
192 <7/15(Fri.) 14:00> Electronic quasiparticles in the quantum dimer model 2016.07.12 68173
191 <March 8(Tue) 18:00> Unsolved puzzles of Gamma-Ray Bursts 2016.03.03 67904
190 <Nov.20(Wed.)>At the End of Space and Time: Imaging the Black Hole in M 87 2019.11.14 67799
189 <3/13> Quantum computing using solid state nano-devices 2013.03.08 67732
188 <3/14> Proto-neutron star 2012.03.08 67660
187 <March.18(Fri) 11:00> High Pressure Synthesis and Characterization of Non-Oxide Superconductors 2016.03.14 67626
186 <10/24> Dung-hai Lee 교수와의 간담회 2012.10.23 67554
185 <11/14> Next Generation LED 2012.11.08 67305
184 <May 04(Tue.)>Flat bands and the geometry of Bloch wave function 2021.04.27 67297
183 <May. 11(Wed.) 4:30 PM> In-situ x-ray studies of functional oxides for energy systems 2016.05.23 67095