A C-terminal domain conserved in precursor processing proteases is required for intramolecular N-terminal maturation of pro-Kex2 protease

EMBO J. 1994 May 15;13(10):2280-8.


The Kex2 protease of the yeast Saccharomyces cerevisiae is the prototype of a family of eukaryotic subtilisin homologs thought to process prohormones and other precursors in the secretory pathway. Deletion analysis of Kex2 protease shows that a sequence of 154-159 residues carboxyl to the subtilisin domain is essential for the formation of active enzyme. Disruption of this region, termed the 'P-domain', blocks the normally rapid intra-molecular cleavage of the N-terminal pro-segment of pro-Kex2 protease in the endoplasmic reticulum (ER). The C-terminal boundary of the P-domain coincides closely with the endpoint of similarity between Kex2 protease and its mammalian homologues. The conservation of and functional requirement for the P-domain sharpens the distinction between a 'Kex2 family' of processing enzymes and degradative 'subtilases', and implies that the Kex2-related enzymes have in common entirely novel structural features that are important in the maturation of precursor polypeptide substrates. Failure to cleave the N-terminal pro-domain, due either to truncation of the P-domain or to mutation of the active site histidine or serine, results in stable, intracellular retention of pro-enzyme, apparently in the ER. Thus pro-Kex2 protease appears to contain an ER retention signal which is removed or destroyed by cleavage of the pro-domain.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites / genetics
  • Conserved Sequence
  • DNA Mutational Analysis
  • Endoplasmic Reticulum / metabolism
  • Enzyme Precursors / genetics
  • Enzyme Precursors / metabolism*
  • Fungal Proteins / metabolism
  • Molecular Sequence Data
  • Proprotein Convertases*
  • Protein Precursors / genetics
  • Protein Precursors / metabolism*
  • Protein Processing, Post-Translational*
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Deletion
  • Sequence Homology, Amino Acid
  • Structure-Activity Relationship
  • Subtilisins / biosynthesis*
  • Subtilisins / genetics


  • Enzyme Precursors
  • Fungal Proteins
  • Protein Precursors
  • Saccharomyces cerevisiae Proteins
  • Proprotein Convertases
  • Subtilisins
  • KEX2 protein, S cerevisiae