[May 22, 2014] 이종봉 교수 와이즈 토토 앱 - Loading Dynamics of a Sliding DNA clamp

DNA 복제 단백질인 β clamp가 DNA에 loading되는 과정을 single-molecule Förster Resonance Energy Transfer (FRET)와 single-molecule polarization 기술을 이용하여 실시간으로 관측하였다. 본 와이즈 토토 앱결과는 Angewandte Chemie에 게제되었으며 (2014년 5월 22일), 이종봉 교수 실험실의 조원기 박사(제 1저자)와 김대형 학생(공저자)이 실험을 수행하였다.

Sliding DNA 와이즈 토토 앱s are loaded at a ss/dsDNA junction by a 와이즈 토토 앱 loader that depends on ATP binding for 와이즈 토토 앱 opening. Sequential ATP hydrolysis results in closure of the 와이즈 토토 앱 so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β 와이즈 토토 앱 in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ 와이즈 토토 앱 loader resulted in closure of the 와이즈 토토 앱 in 0.3 s, and after 0.7 s in the closed conformation, the 와이즈 토토 앱 was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the 와이즈 토토 앱 rotated in plane by approximately 8° during 와이즈 토토 앱 closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β 와이즈 토토 앱 during loading at a ss/dsDNA junction.