Unfolding of colicin A during its translocation through the Escherichia coli envelope as demonstrated by disulfide bond engineering. - Archive ouverte HAL
Article Dans Une Revue Journal of Biological Chemistry Année : 1994

Unfolding of colicin A during its translocation through the Escherichia coli envelope as demonstrated by disulfide bond engineering.

Résumé

Three double cysteine mutants, each possessing a disulfide bond in its pore-forming domain, were used to study the translocation of colicin A through the Escherichia coli envelope. These mutated colicins were able to exert their in vivo channel activity only after their disulfide bonds had been reduced by dithiothreitol. In solution, the reduction of the disulfide bonds by dithiothreitol was a slow process whose kinetics depended on the position of the disulfide bond (t1/2 varying between 35 and 100 s). This t1/2 was strongly decreased (t1/2 = 8-9 s) upon predenaturation of the mutated colicins with urea. The t1/2 values of reduction of the mutants bound to E. coli-sensitive cells were similar to those of predenatured colicins. This suggested that the interaction of the oxidized double cysteine mutants with the E. coli envelope triggered their unfolding. The disulfide bonds did not prevent but delayed the translocation of the colicins. The amplitude of the delay and the time at which it occurred during translocation depended on the position of the disulfide bond. We could discriminate between the delays accumulated during binding to the receptor and those during the translocation via OmpF and the Tol proteins.
Fichier principal
Vignette du fichier
PIIS0021925817314655.pdf (2.41 Mo) Télécharger le fichier
Origine Publication financée par une institution

Dates et versions

hal-02440945 , version 1 (02-12-2021)

Identifiants

Citer

Denis Duché, D. Baty, M. Chartier, L. Letellier. Unfolding of colicin A during its translocation through the Escherichia coli envelope as demonstrated by disulfide bond engineering.. Journal of Biological Chemistry, 1994, 269 (40), pp.24820-5. ⟨10.1016/S0021-9258(17)31465-5⟩. ⟨hal-02440945⟩
25 Consultations
25 Téléchargements

Altmetric

Partager

More