6fg4

Publication Abstract from PubMed

Members of the Staphylococcus aureus phenol-soluble modulin (PSM) peptide family are secreted as functional amyloids that serve diverse roles in pathogenicity and may be present as full-length peptides or as naturally occurring truncations. We recently showed that the activity of PSMalpha3, the most toxic member, stems from the formation of cross-alpha fibrils, which are at variance with the cross-beta fibrils linked with eukaryotic amyloid pathologies. Here, we show that PSMalpha1 and PSMalpha4, involved in biofilm structuring, form canonical cross-beta amyloid fibrils wherein beta-sheets tightly mate through steric zipper interfaces, conferring high stability. Contrastingly, a truncated PSMalpha3 has antibacterial activity, forms reversible fibrils, and reveals two polymorphic and atypical beta-rich fibril architectures. These architectures are radically different from both the cross-alpha fibrils formed by full-length PSMalpha3, and from the canonical cross-beta fibrils. Our results point to structural plasticity being at the basis of the functional diversity exhibited by S. aureus PSMalphas.

Extreme amyloid polymorphism in Staphylococcus aureus virulent PSMalpha peptides.,Salinas N, Colletier JP, Moshe A, Landau M Nat Commun. 2018 Aug 29;9(1):3512. doi: 10.1038/s41467-018-05490-0. PMID:30158633^[1]

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