Send to

Choose Destination
Biochem Biophys Res Commun. 2006 May 19;343(4):1159-64.

A unique mechanism for the processive movement of single-headed myosin-IX.

Author information

Department of Biophysical Engineering, Osaka University 1-3, Machikaneyama, Toyonaka, Osaka 560-8531, Japan.


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 ( approximately 20nm) 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.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center