PMID: 21896717

Authors:

Salgado PS, Yan R, Taylor JD, Burchell L, Jones R, Hoyer LL, Matthews SJ, Simpson PJ, Cota E

Title:

Structural basis for the broad specificity to host-cell ligands by the pathogenic fungus Candida albicans.

Journal:

Proc Natl Acad Sci U S A. 2011 Sep 20;108(38):15775-9. Epub 2011 Sep 6.

Abstract:

Candida albicans is the most prevalent fungal pathogen in humans and a major source of life-threatening nosocomial infections. The Als (agglutinin-like sequence) glycoproteins are an important virulence factor for this fungus and have been associated with binding of host-cell surface proteins and small peptides of random sequence, the formation of biofilms and amyloid fibers. High-resolution structures of N-terminal Als adhesins (NT-Als; up to 314 amino acids) show that ligand recognition relies on a motif capable of binding flexible C termini of peptides in extended conformation. Central to this mechanism is an invariant lysine that recognizes the C-terminal carboxylate of ligands at the end of a deep-binding cavity. In addition to several protein-peptide interactions, a network of water molecules runs parallel to one side of the ligand and contributes to the recognition of diverse peptide sequences. These data establish NT-Als adhesins as a separate family of peptide-binding proteins and an unexpected adhesion system for primary, widespread protein-protein interactions at the Candida/host-cell interface.