Fig. 4

Distribution of Nt-biased mass shifts across positions in protein sequence. The widths of traces within each row represent the density of unique positions identified for the mass shift indicated to the left along target proteins, normalized by protein length (x-axis). Traces are plotted symmetrically about the x-axis. Mass shifts are ranked from top to bottom by combined p-value from the Fisher’s exact test for N-terminal modification enrichment across all three replicates (see section “N-terminal and C-terminal Modifications” and Table 4), with mass shifts having the strongest N-terminal enrichment at the top