Force-producing ADP state of myosin bound to actin.
Proc Natl Acad Sci U S A
; 113(13): E1844-52, 2016 Mar 29.
Article
en En
| MEDLINE
| ID: mdl-26976594
ABSTRACT
Molecular motors produce force when they interact with their cellular tracks. For myosin motors, the primary force-generating state has MgADP tightly bound, whereas myosin is strongly bound to actin. We have generated an 8-Å cryoEM reconstruction of this state for myosin V and used molecular dynamics flexed fitting for model building. We compare this state to the subsequent state on actin (Rigor). The ADP-bound structure reveals that the actin-binding cleft is closed, even though MgADP is tightly bound. This state is accomplished by a previously unseen conformation of the ß-sheet underlying the nucleotide pocket. The transition from the force-generating ADP state to Rigor requires a 9.5° rotation of the myosin lever arm, coupled to a ß-sheet rearrangement. Thus, the structure reveals the detailed rearrangements underlying myosin force generation as well as the basis of strain-dependent ADP release that is essential for processive myosins, such as myosin V.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Adenosina Difosfato
/
Actinas
/
Miosina Tipo V
Límite:
Humans
Idioma:
En
Año:
2016
Tipo del documento:
Article