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 1019943
442 <Oct. 28(Wed.) 4:30 PM> Anomalous diffusion of single-molecules in living cells: at the interface of biology and statistical physics 2015.10.19 89969
441 <Oct.20(Tue) 16:00> Electromagnetic Response and Thermomagnetic Instabilities in Three-Dimensional Nanostructured Superconductors file 2015.10.15 83987
» <Oct.15(Thu) 16:30> Single-Molecule Approach to Homology Search & Strand Exchange in Homologous Recombination 2015.10.12 94957
439 <Oct. 14(Wed.) 4:30 PM> 국방과학기술과 물리학 2015.10.07 64753
438 <Oct. 20(Tue.) 2:00 PM> High-throughput Synthesis of Oxide Thin Films 2015.10.05 109793
437 <Oct. 7(Wed.) 4:30 PM> Observing Ultra High Energy Cosmic Rays with your Smartphone 2015.10.02 124048
436 학술세미나 개최 안내: Local Modes in Vibrational (and Rotational) Spectroscopy file 2015.10.01 54703
435 <Sep. 30(Wed.) 4:30 PM>Local electronic structures of stacking grain boundary in bilayer graphene 2015.09.23 84425
434 <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 148568
433 <Sep. 18(Fri.) 4:00 PM> Special seminar 2015.09.16 56505
432 <Sep. 16(Wed.) 4:30 PM> Watching molecular targets in living bodies: the cutting edge in clinical medicine 2015.09.09 69418
431 <Sep. 9(Wed.) 4:30 PM> Electronic structures of strongly-correlated systems 2015.09.03 78133
430 <8/29(토)> 세미나 개최 안내 2015.09.01 61701
429 2015학년도 2학기 콜로퀴움 일정 2015.08.06 88040
428 <6/9(화)> 세미나 개최 안내 2015.06.09 64545
427 <6/10(수) 오후4:30분> Closing in on the Axion Dark Matter hypothesis 2015.06.03 63695
426 <6/2(화)> 세미나 개최 안내 2015.06.01 59721
425 <6/3(수) 오후4:30분> The Quest for Dark Matter: Discovering Its Nature Underground? 2015.05.28 69564
424 <5/26(화)> 세미나 개최 안내 2015.05.27 62393
423 <5/27(수) 오후4:30분>Controlling phases in epitaxial transition metal oxide thin films 2015.05.21 102391