Abstract

BAKAS, Laura; MATE, Sabina; VAZQUEZ, Romina  and  HERLAX, Vanesa. Action mechanism of Escherichia coli alpha-hemolysin toxin. Acta bioquím. clín. latinoam. [online]. 2013, vol.47, n.2, pp.353-361. ISSN 0325-2957.

Escherichia coli is one of the predominant species of facultative anaerobes in the human gut, and in the majority of the cases it is harmless to the host. Some strains of this species can translocate to blood and cause infection such as urinary infection, septicemia and meningitis. These are the uropathogenic E. coli strains (UPEC) that secrete a number of virulence factors. The latter include a number of secreted toxins, iron-acquisition systems, adhesins, and capsular antigens. Secreted toxins include HlyA, the cytotoxic necrotizing factor-1 (CNF-1). In this review an exhaustive description of the toxin has been delineated, including its synthesis, maturation, and export from the bacteria. The acylation of the protein at two internal lysine residues gives the toxin its virulence, by exposing intrinsic disordered regions that are essential in different steps of the toxin's mechanism of action. The further exposure of regions involved in the protein-protein interaction within the oligomerization process is responsG-ible for the permeability induced in all the target cells. Based on the already known structural and functional characteristics of HlyA, the potential use in toxin-based therapy is presented.

Keywords : Toxins; Oligomerization; Membrane microdomains; Immunotoxins; Intrinsic disordered regions.

        · abstract in Spanish | Portuguese     · text in Spanish     · Spanish ( pdf )