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 1007687
462 2008학년도 1학기 콜로퀴움 일정 안내 2008.03.04 81698
461 <3/14>Adaptive Optics for the Human Eye and Ophthalmic Applications 2008.03.12 196206
460 <3/21> Advanced Quantum Beams Based on Electron Accelerators and Lasers 2008.03.14 75007
459 2008학년도 1학기 물리세미나1 강의계획서 2008.03.18 74567
458 영어초록 예시 2008.03.18 87157
457 essay 작성요령 2008.03.18 79143
456 <3/28> Nanoscale Physics related to Resistance Switchings &Its Applications to Resistance RAM 2008.03.24 73571
455 <4/4> Novel multi-bit magnetic tagging technique for high-throughput chemical analysis 2008.03.31 109381
454 <4/11> 방사광 연 X선을 이용한 미시적 물성 연구 2008.04.07 88068
453 <5/2>방사선을 이용한 무통/무혈 수술 2008.04.28 106202
452 <5/9> Nonequilibrium Critical Phenomena: Fractals and Self-Organized Criticality 2008.05.06 92539
451 <5/16>모의실험을 이용한 물리학습 2008.05.13 75178
450 <5/23> Nanotechnology in Korea: Present Status and Perspective 2008.05.21 88637
449 <5/30> DNA 나노기술(DNA Nanotechnology) 2008.05.26 111127
448 <9/5> Dark Matter and Dark Energy in Cosmology 2008.09.01 78359
447 <9/19> Downscaling of self-aligned, all-printed polymer thin-film transistors 2008.09.16 128674
446 <9/26> High Energy Physics as e-Science 2008.09.22 76735
445 <10/10>Self-reconfigurable robots 2008.10.07 85108
444 <10/17> Graphitic Carbon Nanostructures 2008.10.27 107177
443 <10/31> 학부생을 위한 입자물리학및 끈이론 소개 2008.10.27 71406