Extended sugar slide function for the periplasmic coiled coil domain of ScrY.
J Mol Biol
; 300(4): 687-95, 2000 Jul 21.
Article
en En
| MEDLINE
| ID: mdl-10891263
ABSTRACT
Several bacterial outer membrane proteins have a periplasmic extension whose structure and function remain elusive. Here, the structure/function relationship of the N-terminal periplasmic domain of the sucrose-specific outer membrane channel ScrY was investigated. Circular dichroism and analytical centrifugation demonstrated that the N-terminal domain formed a parallel, three-stranded coiled coil. When this domain was fused to the maltose-specific channel LamB, permeation of maltooligosaccharides in liposomes increased with increasing sugar chain length whereas wild-type LamB showed the opposite effect. Current fluctuation analysis demonstrated increased off-rates for sugar transport through the fusion protein. Moreover, equilibrium dialysis showed an affinity of sucrose for the isolated N-terminal peptide. Together these results demonstrate a novel function for coiled coil domains, operating as an extended sugar slide.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Porinas
/
Periplasma
/
Metabolismo de los Hidratos de Carbono
Idioma:
En
Revista:
J Mol Biol
Año:
2000
Tipo del documento:
Article
País de afiliación:
Suiza