Model for processive movement of myosin V and myosin VI

Myosin V and myosin VI are two classes of two-headed molecular motors of the myosin superfamily that move processively along helical actin filaments in opposite directions. Here we present a hand-over-hand model for their processive movements. In the model, the moving direction of a dimeric molecular motor is automatically determined by the relative orientation between its two heads at free state and its head's binding orientation on track filament. This determines that myosin V moves toward the barbed end and myosin VI moves toward the pointed end of actin. During the moving period in one step, one head remains bound to actin for myosin V whereas two heads are detached for myosin VI: The moving manner is determined by the length of neck domain. This naturally explains the similar dynamic behaviors but opposite moving directions of myosin VI and mutant myosin V (the neck of which is truncated to only one-sixth of the native length). Because of different moving manners, myosin VI and mutant myosin V exhibit significantly broader step-size distribution than native myosin V. However, all three motors give the same mean step size of 36 nm (the pseudo-repeat of actin helix). Using the model we study the dynamics of myosin V quantitatively, with theoretical results in agreement with previous experimental ones..

Medienart:	Preprint

Erscheinungsjahr:	2003
Erschienen:	2003

Enthalten in:	arXiv.org - (2003) vom: 30. Dez. Zur Gesamtaufnahme - year:2003

Sprache:	Englisch

Beteiligte Personen:	Xie, Ping [VerfasserIn] Dou, Shuo-Xing [VerfasserIn] Wang, Peng-Ye [VerfasserIn]

Links:	Volltext [lizenzpflichtig] Volltext [kostenfrei]

doi:	10.1088/1009-1963/14/4/018

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PPN (Katalog-ID):	XAR014670496