The elongation of yeast prion fibers involves separable steps of association and conversion.

ABSTRACT: A self-perpetuating change in the conformation of the translation termination factor Sup35p is the basis for the prion [PSI+], a protein-based genetic element of Saccharomyces cerevisiae. In a process closely allied to in vivo conversion, the purified soluble, prion-determining region of Sup35p (NM) converts to amyloid fibers by means of nucleated conformational conversion. First, oligomeric species convert to nuclei, and these nuclei then promote polymerization of soluble protein into amyloid fibers. To elucidate the nature of the polymerization step, we created single-cysteine substitution mutants at different positions in NM to provide unique attachment sites for various probes. In vivo, the mutants behaved like wild-type protein in both the [psi-] and [PSI+] states. In vitro, they asse

SUBMITTER: Scheibel T 

PROVIDER: S-EPMC356943 | biostudies-literature | 2004 Feb

REPOSITORIES: biostudies-literature