ISOLATION OF SUPPRESSORS OF TEMPERATURE-SENSITIVE FOLDING MUTATIONS

Mutations in the tailspike gene (gene 9) of Salmonella typhimurium pha ge P22 have been used to identify amino acid interactions during the f olding of a polypeptide chain. Since temperature-sensitive folding (ts f) mutations cause folding defects in the P22 tailspike polypeptide ch ain, it is likely that mutants derived from these and correcting the o riginal tsf defects (second-site intragenic suppressors) identify inte ractions during the folding pathway. We report the isolation and ident ification of second-site revertants to tsf mutants.