Structural mechanism of voltage-dependent gating in an isolated voltage-sensing domain.
Nat Struct Mol Biol
; 21(3): 244-52, 2014 Mar.
Article
en En
| MEDLINE
| ID: mdl-24487958
ABSTRACT
The transduction of transmembrane electric fields into protein motion has an essential role in the generation and propagation of cellular signals. Voltage-sensing domains (VSDs) carry out these functions through reorientations of positive charges in the S4 helix. Here, we determined crystal structures of the Ciona intestinalis VSD (Ci-VSD) in putatively active and resting conformations. S4 undergoes an ~5-Å displacement along its main axis, accompanied by an ~60° rotation. This movement is stabilized by an exchange in countercharge partners in helices S1 and S3 that generates an estimated net charge transfer of ~1 eo. Gating charges move relative to a ''hydrophobic gasket' that electrically divides intra- and extracellular compartments. EPR spectroscopy confirms the limited nature of S4 movement in a membrane environment. These results provide an explicit mechanism for voltage sensing and set the basis for electromechanical coupling in voltage-dependent enzymes and ion channels.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
3_ND
Problema de salud:
3_neglected_diseases
/
3_zoonosis
Asunto principal:
Ciona intestinalis
/
Estructura Terciaria de Proteína
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Nat Struct Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos