Survey of amino-terminal proteolytic cleavage sites in mitochondrial precursor proteins: leader peptides cleaved by two matrix proteases share a three-amino acid motif.
Year: 1989
Type: article
Abstract: We have compiled sequences of precursor proteins for 50 mitochondrial proteins for which the mature amino terminus has been determined by amino acid sequence analysis. Included in this set are 8 precursors that have leader peptides that are cleaved in two places by mitochondrial matrix proteases. When these eight leader peptides are aligned and compared, a highly conserved three-amino acid motif is identified as being common to this class of leader peptides. This motif includes an arginine at position -10, a hydrophobic residue at position -8, and serine, threonine, or glycine at position -5 relative to the mature amino terminus. The initial cleavage of these peptides by matrix processing protease occurs within the motif, between residues at -9 and -8, such that arginine at position -10 is at position -2 relative to the cleaved bond. The rest of the motif is within the octapeptide removed by subsequent cleavage catalyzed by intermediate-specific protease. An additional 14 leader peptides in this collection (all of those that contain an arginine at -10) conform to this motif. Assuming that these 14 precursors are matured in two steps, we compared the internal cleavage sites at position -8 with the ends of the other 30 leader peptides in the collection. We find that 74% of matrix processing protease cleavage sites follow an arginine at position -2 relative to cleavage.
Authors: J P Hendrick, P E Hodges, L E Rosenberg
Institution: Yale University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2141894532