Crystal Structure of the Vanadate-Inhibited Ca(2+)-ATPase.
Structure
; 24(4): 617-623, 2016 Apr 05.
Article
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| MEDLINE
| ID: mdl-27050689
ABSTRACT
Vanadate is the hallmark inhibitor of the P-type ATPase family; however, structural details of its inhibitory mechanism have remained unresolved. We have determined the crystal structure of sarcoplasmic reticulum Ca(2+)-ATPase with bound vanadate in the absence of Ca(2+). Vanadate is bound at the catalytic site as a planar VO3(-) in complex with water and Mg(2+) in a dephosphorylation transition-state-like conformation. Validating bound VO3(-) by anomalous difference Fourier maps using long-wavelength data we also identify a hitherto undescribed Cl(-) site near the dephosphorylation site. Crystallization was facilitated by trinitrophenyl (TNP)-derivatized nucleotides that bind with the TNP moiety occupying the binding pocket that normally accommodates the adenine of ATP, rationalizing their remarkably high affinity for E2P-like conformations of the Ca(2+)-ATPase. A comparison of the configurations of bound nucleotide analogs in the E2·VO3(-) structure with that in E2·BeF3(-) (E2P ground state analog) reveals multiple binding modes to the Ca(2+)-ATPase.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Vanadatos
/
ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico
Límite:
Animals
Idioma:
En
Año:
2016
Tipo del documento:
Article