期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：26
页码：9630-9635
DOI：10.1073/pnas.0402914101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Class V myosin (myosin-V) was first found as a processive motor that moves along an actin filament with large ({approx}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 ({approx}32-nm) steps, suggesting that a novel mechanism is operating for successive myosin movement.
