Protein misfolding and amyloid assembly have long been recognized as being responsible for many devastating human diseases. Recent findings indicate that amyloid assemblies may facilitate crucial biological processes from bacteria to mammals. This review focuses on the mechanistic understanding of amyloid formation, including the transformation of initially innocuous proteins into oligomers and fibrils. The result is a competing folding and assembly energy landscape, which contains a number of routes by which the polypeptide chain can convert its primary sequence into functional structures, dysfunctional assemblies, or epigenetic entities that provide both threats and opportunities in the evolution of life.
