Fig. 1: S. aureus-secreted functional amyloids: Hypothesis and structural characterization of the PSMα amyloids.

a PSMα amyloid fibrils bind β-lactams and catalyze their degradation through amide bond hydrolysis. b Sequences of PSMα 1–4. Anionic, cationic, and nucleophilic residues are marked in red, blue, and turquoise, respectively. The formal charge (F.C.) of each sequence is noted on the right. c Cryo-TEM images of the peptides (concentration 300 µM). Bars correspond to 200 nm. All PSMα samples were pre-incubated in water for two hours and buffered with Hepes prior to image acquisition. d Amyloid staining with Amytracker 680 (excitation 552 nm, emission 654 nm, PSMα concentrations were 300 µM). Data presented in box-and-whisker plot, with mean line and quartile calculation using inclusive median, N = 3. e Circular dichroism (CD) spectra of the peptides (concentration 170 µM, peptides dissolved in Hepes buffer, pH = 7.4). Source data are provided as a Source Data file.