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 1020061
462 <3/16> Inelastic X-ray Scattering: past, present, and the future 2011.03.10 85503
461 <10/10>Self-reconfigurable robots 2008.10.07 85448
460 <5/8>Recent trend of thin film battery 2009.05.06 85436
459 2015학년도 1학기 콜로퀴움 일정 file 2015.02.27 85166
458 <7월27일>Correlated topological phases in 3D complex oxides via Green's functions 2012.07.27 85156
457 <6/9> Status and Prospects of Big Science in Korea 2006.06.05 85049
456 <10/8(수> Astrophysical probes of Dark Matter, the case of the Milky Way 2014.10.01 85025
455 <5/29> Study on the electronic interactions in solids under high magnetic fields 2013.05.23 84922
454 <12/21(Fri) 3:00pm ~ > Quasilocal Smarr Relations / Expanding Universe and Dynamical Compactification Using Yang-Mills Instantons 2018.12.17 84882
453 <10/12> Kondo Effect in a Quantum-Dot-Topological-Superconductor Junction: A Numerical Renormalization Group Analysis 2012.10.08 84816
452 <5/16(Thu.) 14:00 ~ >The Chiral anomaly without Landau levels 2019.05.08 84567
451 <10/17> The Interface Induced Magnetism 2012.10.11 84533
450 <9/26(Thu.) 4:30 pm ~ > Neutrino Physics and Dark Matter search in IBS 2019.09.24 84508
449 <11/13(Tue.) 11:00am>Hund’s coupling driven role of $d_{3z^2-r^2}$ in stabilizing the hole-doped antiferromagnetic state in cuprates 2018.11.09 84468
448 <Sep. 30(Wed.) 4:30 PM>Local electronic structures of stacking grain boundary in bilayer graphene 2015.09.23 84431
447 <7/21> Next generation cryogenic free 1.5T MgB2-magnet based MRI 2010.07.20 84170
446 <7/24(Mon.)11:00>Antenna Arrays for Astroparticle Physics: Radio Detection of High-Energy Cosmic Rays 2017.07.19 84161
445 <12/14> Breakup-Fusion and Knockout-Fusion Approach to Pre-Equilibrium Processes 2009.12.11 84139
444 <Oct.20(Tue) 16:00> Electromagnetic Response and Thermomagnetic Instabilities in Three-Dimensional Nanostructured Superconductors file 2015.10.15 83998
443 <4/15(수) 오후4:30분> Who is SHE? 2015.04.08 83950