Myosin VI dimerization triggers an unfolding of a three-helix bundle in order to extend its reach.
Mol Cell
; 35(3): 305-15, 2009 Aug 14.
Article
em En
| MEDLINE
| ID: mdl-19664948
ABSTRACT
Myosin VI challenges the prevailing theory of how myosin motors move on actin the lever arm hypothesis. While the reverse directionality and large powerstroke of myosin VI can be attributed to unusual properties of a subdomain of the motor (converter with a unique insert), these adaptations cannot account for the large step size on actin. Either the lever arm hypothesis needs modification, or myosin VI has some unique form of extension of its lever arm. We determined the structure of the region immediately distal to the lever arm of the motor and show that it is a three-helix bundle. Based on C-terminal truncations that display the normal range of step sizes on actin, CD, fluorescence studies, and a partial deletion of the bundle, we demonstrate that this bundle unfolds upon dimerization of two myosin VI monomers. This unconventional mechanism generates an extension of the lever arm of myosin VI.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cadeias Pesadas de Miosina
Limite:
Animals
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos