Insights into the inhibited form of the redox-sensitive SufE-like sulfur acceptor CsdE.
PLoS One
; 12(10): e0186286, 2017.
Article
em En
| MEDLINE
| ID: mdl-29045454
ABSTRACT
Sulfur trafficking in living organisms relies on transpersulfuration reactions consisting in the enzyme-catalyzed transfer of S atoms via activated persulfidic S across protein-protein interfaces. The recent elucidation of the mechanistic basis for transpersulfuration in the CsdA-CsdE model system has paved the way for a better understanding of its role under oxidative stress. Herein we present the crystal structure of the oxidized, inactivated CsdE dimer at 2.4 Å resolution. The structure sheds light into the activation of the Cys61 nucleophile on its way from a solvent-secluded position in free CsdE to a fully extended conformation in the persulfurated CsdA-CsdE complex. Molecular dynamics simulations of available CsdE structures allow to delineate the sequence of conformational changes underwent by CsdE and to pinpoint the key role played by the deprotonation of the Cys61 thiol. The low-energy subunit orientation in the disulfide-bridged CsdE dimer demonstrates the likely physiologic relevance of this oxidative dead-end form of CsdE, suggesting that CsdE could act as a redox sensor in vivo.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Conformação Proteica
/
Liases de Carbono-Enxofre
/
Enxofre
/
Proteínas de Escherichia coli
/
RNA Helicases DEAD-box
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
PLoS One
Ano de publicação:
2017
Tipo de documento:
Article