A one-headed class V myosin molecule develops multiple large (approximately 32-nm) steps successively.
Class V myosin (myosin-V) was first found as a processive motor that moves along an actin filament with large ( approximately 36-nm) successive steps and plays an important role in cargo transport in cells. Subsequently, several other myosins have also been found to move processively. Because myosin-V has two heads with ATP- and actin-binding sites, the mechanism of successive movement has been generally explained based on the two-headed structure. However, the fundamental problem of whether the two-headed structure is essential for the successive movement has not been solved. Here, we measure motility of engineered myosin-V having only one head by optical trapping nanometry. The results show that a single one-headed myosin-V undergoes multiple successive large (approximately 32-nm) steps, suggesting that a novel mechanism is operating for successive myosin movement.
Watanabe
Tomonobu M
TM
Formation of Soft Nanomachines, Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, and Department of Biophysical Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Tanaka
Hiroto
H
Iwane
Atsuko Hikikoshi
AH
Maki-Yonekura
Saori
S
Homma
Kazuaki
K
Inoue
Akira
A
Ikebe
Reiko
R
Yanagida
Toshio
T
Ikebe
Mitsuo
M
D008841:Actin Cytoskeleton / Q000737:chemistry / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002645:Chickens; D008954:Models, Biological; D009068:Movement; D024701:Myosin Type V / Q000737:chemistry* / Q000378:metabolism*; D015202:Protein Engineering; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011817:Rabbits; D014982:Xenopus laevis
D000199:Actins; D000255:Adenosine Triphosphate; D024701:Myosin Type V