PROTEIN SPLICING IN THE YEAST VMA1 PROTOZYME - EVIDENCE FOR AN INTRAMOLECULAR REACTION

Protein splicing is an autocatalytic reaction of a single polypeptide in which a spliced intervening sequence is excised out and the two ext ernal regions are Ligated with the peptide bond to field two mature pr oteins, We examined the reaction mechanism using a folding-dependent i n vitro protein splicing system, Protein splicing proceeds at an optim al pH of 7 and is an intramolecular reaction, The reaction is not inhi bited by potential protease inhibitors, suggesting that its mechanism is different from those catalyzed by known proteases. (C) 1997 Federat ion of European Biochemical Societies.