Crystal structure of a colicin N fragment suggests a model for toxicity

107Citations
Citations of this article
31Readers
Mendeley users who have this article in their library.

Abstract

Background: Pore-forming colicins are water-soluble bacteriocins capable of binding to and translocating through the Escherichia coli cell envelope. They then undergo a transition to a transmembrane ion channel in the cytoplasmic membrane leading to bacterial death. Colicin N is the smallest pore-forming colicin known to date (40 kDa instead of the more usual 60 kDa) and the crystal structure of its membrane receptor, the porin OmpF, is already known. Structural knowledge of colicin N is therefore important for a molecular understanding of colicin toxicity and is relevant to toxic mechanisms in general. Results: The crystal structure of colicin N reveals a novel receptor-binding domain containing a six-stranded antiparallel β sheet wrapped around the 63 Å long N-terminal α helix of the pore-forming domain. The pore-forming domain adopts a ten α-helix bundle that has been observed previously in the pore-forming domains of colicin A, la and E1. The translocation domain, however, does not appear to adopt any regular structure. Models for receptor binding and translocation through the outer membrane are proposed based on the structure and biochemical data. Conclusions: The colicin N-ompF system is now the structurally best-defined translocation pathway. Knowledge of the colicin N structure, coupled with the structure of its receptor, OmpF, and previously published biochemical data, limits the numerous possibilities of translocation and leads to a model in which the translocation domain inserts itself through the porin pore, the receptor-binding domain stays outside and the pore-forming domain translocates along the outer wall of the trimeric porin channel.

Cite

CITATION STYLE

APA

Vetter, I. R., Parker, M. W., Tucker, A. D., Lakey, J. H., Pattus, F., & Tsernoglou, D. (1998). Crystal structure of a colicin N fragment suggests a model for toxicity. Structure, 6(7), 863–874. https://doi.org/10.1016/S0969-2126(98)00088-4

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free