کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1939586 | 1050763 | 2006 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A unique mechanism for the processive movement of single-headed myosin-IX A unique mechanism for the processive movement of single-headed myosin-IX](/preview/png/1939586.png)
It has been puzzled that in spite of its single-headed structure, myosin-IX shows the typical character of processive motor in multi-molecule in vitro motility assay, because this cannot be explained by hand-over-hand mechanism of the two-headed processive myosins. Here, we show direct evidence of the processive movement of myosin-IX using two different single molecule techniques. Using optical trap nanometry, we found that myosin-IX takes several large (∼20 nm) steps before detaching from an actin filament. Furthermore, we directly visualized the single myosin-IX molecules moving on actin filaments for several hundred nanometers without dissociating from actin filament. Since myosin-IX processively moves without anchoring the neck domain, the result suggests that the neck tilting is not involved for the processive movement of myosin-IX. We propose that the myosin-IX head moves processively along an actin filament like an inchworm via a unique long and positively charged insertion in the loop 2 region of the head.
Journal: Biochemical and Biophysical Research Communications - Volume 343, Issue 4, 19 May 2006, Pages 1159–1164