Prevalence of individual RKPT residues and prevalence of carbonylated form in experimentally measured peptides combining all 3 biological replicates of both conditions for each organism. Ratios are given above each pair of bars. All proportions are significantly different between each RKPT and their respective carbonylation state by two-tailed z-test of two proportions (p-values < 0.01; see Materials and Methods), meaning carbonylated proportions are not determined simply by relative prevalence of RKPT. See also Appendix Fig S1. 