Amino acid occurrence of putative target molecules for different PCSK enzymes. Twenty residues (P10 - P10') around the PCSK cleavage sites of putative target molecules have been plotted for each PCSK enzymes (PCSK1-PCSK7, columns 1 - 7, respectively, in each position). Rows correspond to different amino acids. Blue color indicates increased occurrence of a particular amino acid residue type in certain position of the putative substrate when all PCSKs are considered, whereas red colors mean low occurrence of a specific amino acid. White indicates an average occurrence frequency of a specific amino acid. The increase or decrease in occurrence is shown as a scale of percentages and a combined data containing all PCSKs has been used as a comparison point. The scaling (-6 percentage to +6 percentage) is shown as a color gradient below the figure. The potentially scissile bond P1-P1' is marked with scissors.