Processing of the Papain Precursor THE IONIZATION STATE OF A CONSERVED AMINO ACID MOTIF WITHIN THE Pro REGION PARTICIPATES IN THE REGULATION OF INTRAMOLECULAR PROCESSING *

The cysteine protease papain is synthesized as a 40-kDa inactive precursor with a 107-amino-acid N-terminal pro region. Although sequence conservation in the pro region is lower than in the mature proteases, a conserved motif (Gly-Xaa-Asn-Xaa-Phe-Xaa-Asp-36, papain precursor numbering) was found within the pro region of cysteine proteases of the papain superfamily. To determinate the function to this conserved motif, we have mutagenized at …