Modèle d'étude de l'insertion des protéines membranaires

Abstract

Colicin A from Citrobacter freundii and aerolysin from Aeromonas hydrophila are representative of two classes of pore-forming toxins. Colicin A, an alpha-helical protein, contains an hydrophobic hairpin which is buried inside the structure in solution. It is an << inside out >> membrane protein. Aerolysin is formed almost exclusively of beta-sheet and possesses a very hydrophilic amino acid sequence. It is secreted as an inactive precursor which is activated by proteolytic removal of about 41-43 residues from the C-terminus. The mechanism of membrane insertion and the structure of the membrane bound form of these toxins are discussed.