MRC National Institute for Medical Research, London
Science for Health
Direct observation of myosin molecules moving in response to ATP hydrolysis
08 August 2008
Myosin V is a processive motor protein that carries cargoes within the cell along actin filaments. This work used single molecule fluorescence observations to examine the coordination between ATP hydrolysis, which provides the energy, and the movement itself. Fluorescent labeling enabled both the nucleotide and myosin to be observed simultaneously in real time and with almost nanometre resolution. The work shows that there is tight coupling between ATP hydrolysis and the 36 nm, unidirectional steps taken by the myosin. The study made use of one of the fluorescent ATP analogues, previously developed at NIMR (Webb et al, Biochemistry (2004) 43:14463-14471 Abstract).
This work was made possible by the development of novel analogues of ATP that give a large fluorescence signal, but only when attached to the myosin as it moves along the track of an actin filament. The results provide insight into how the stepping mechanism is coordinated with the gating of the kinetics of ATP hydrolysis between the two heads of the myosin molecule.
Martin Webb
Original article
The research findings are published in full in:
Takeshi Sakamoto, Martin R. Webb, Eva Forgacs, Howard D. White & James R. Sellers
Direct observation of the mechanochemical coupling in myosin Va during processive movement
Nature, Epub ahead of print Publisher abstract
© MRC National Institute for Medical Research
The Ridgeway, Mill Hill, London NW7 1AA
Top of page