5i55

Publication Abstract from PubMed

Amyloids are ordered protein aggregates, found in all kingdoms of life, and are involved in aggregation diseases as well as in physiological activities. In microbes, functional amyloids are often key virulence determinants, yet the structural basis for their activity remains elusive. We determined the fibril structure and function of the highly toxic, 22-residue phenol-soluble modulin alpha3 (PSMalpha3) peptide secreted by Staphylococcus aureus PSMalpha3 formed elongated fibrils that shared the morphological and tinctorial characteristics of canonical cross-beta eukaryotic amyloids. However, the crystal structure of full-length PSMalpha3, solved de novo at 1.45 angstrom resolution, revealed a distinctive "cross-alpha" amyloid-like architecture, in which amphipathic alpha helices stacked perpendicular to the fibril axis into tight self-associating sheets. The cross-alpha fibrillation of PSMalpha3 facilitated cytotoxicity, suggesting that this assembly mode underlies function in S. aureus.

The cytotoxic Staphylococcus aureus PSMalpha3 reveals a cross-alpha amyloid-like fibril.,Tayeb-Fligelman E, Tabachnikov O, Moshe A, Goldshmidt-Tran O, Sawaya MR, Coquelle N, Colletier JP, Landau M Science. 2017 Feb 24;355(6327):831-833. doi: 10.1126/science.aaf4901. PMID:28232575^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.