Investigation of Fibrillation by Amyloidogenic Regions of the Ribosomal S1 Proteins

Abstract

RNA-binding structural S1 domain, belonging to the oligosaccharide/oligonucleotide-binding domain superfamily, is widely distributed and conserved in prokaryotes, archaea, and eukaryotes. Despite the known tendency to aggregation of ribosomal S1 proteins, the tendency of fibrillation by amyloidogenic regions of this family is poorly understood. In this paper, we combined bioinformatics and experimental approaches to study the features of amyloidogenic regions in this family of proteins. Bioinformatics tools were used to assess the propensity for amyloidogenesis on the example of 1331 sequences of ribosomal S1 protein and to identify such regions in various structural domains. We showed that the fraction of amyloidogenic regions for the full-size proteins decreases with increasing protein size. Within individual domains amyloidogenic regions are more often predicted in the C-and N-terminal parts. For the selected and synthesized 11 amyloidogenic peptides from the Escherichia coli and Thermus thermophilus ribosomal S1 proteins, we showed their ability to form amyloid-like fibrils by electron microscopy.