A coupled equilibrium shift mechanism in calmodulin-mediated signal transduction.
Structure
; 16(5): 736-46, 2008 May.
Article
en En
| MEDLINE
| ID: mdl-18462678
ABSTRACT
We used nuclear magnetic resonance data to determine ensembles of conformations representing the structure and dynamics of calmodulin (CaM) in the calcium-bound state (Ca(2+)-CaM) and in the state bound to myosin light chain kinase (CaM-MLCK). These ensembles reveal that the Ca(2+)-CaM state includes a range of structures similar to those present when CaM is bound to MLCK. Detailed analysis of the ensembles demonstrates that correlated motions within the Ca(2+)-CaM state direct the structural fluctuations toward complex-like substates. This phenomenon enables initial ligation of MLCK at the C-terminal domain of CaM and induces a population shift among the substates accessible to the N-terminal domain, thus giving rise to the cooperativity associated with binding. Based on these results and the combination of modern free energy landscape theory with classical allostery models, we suggest that a coupled equilibrium shift mechanism controls the efficient binding of CaM to a wide range of ligands.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Calmodulina
/
Transducción de Señal
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Structure
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
/
BIOTECNOLOGIA
Año:
2008
Tipo del documento:
Article
País de afiliación:
Reino Unido