Single-Molecule Kinetics of the Eukaryotic Initiation Factor 4AI upon RNA Unwinding
Yingjie Sun, Evrim Atas, Lisa M Lindqvist, Nahum Sonenberg, Jerry Pelletier, Amit Meller
Structure | CELL PRESS | Published : 2014
The eukaryotic translation initiation factor 4AI (eIF4AI) is the prototypical DEAD-box RNA helicase. It has a "dumbbell" structure consisting of two domains connected by a flexible linker. Previous studies demonstrated that eIF4AI, in conjunction with eIF4H, bind to loop structures and repetitively unwind RNA hairpins. Here, we probe the conformational dynamics of eIF4AI in real time using single-molecule FRET. We demonstrate that eIF4AI/eIF4H complex can repetitively unwind RNA hairpins by transitioning between an eIF4AI "open" and a "closed" conformation using the energy derived from ATP hydrolysis. Our experiments directly track the conformational changes in the catalytic cycle of eIF4AI ..View full abstract
Awarded by Human Frontiers Science Program (HFSP)
Awarded by Israel Science Foundation
Awarded by Canadian Institutes of Health Research (CIHR)
We acknowledge financial support from the Human Frontiers Science Program (HFSP) (RGP0036-2005) (to A. M. and N.S.), the Israel Science Foundation (845/11) (to A. M.), and the Canadian Institutes of Health Research (CIHR) (MOP-106530) (to J.P.). L. M. L. was a NSERC Alexander Graham Bell (CGSD) fellowship recipient and currently holds a CIHR postdoctoral fellowship, a Bisby Fellowship, and a National Health and Medical Research Council Peter Doherty Early Career Fellowship.