Supplementary Figure 4: Mutational analysis of titin and myosin.
From: Mechanochemical evolution of the giant muscle protein titin as inferred from resurrected proteins
Mutation rates for titin (a) and myosin (b) are estimated as the number of mutations from the ancestral forms to their modern counterparts per 100 residues and per Myr. Overall, mutation rate is double in titin with respect to myosin. Mutation rates for titin and myosin are estimated as the number of mutations from the ancestral forms to their modern counterparts per 100 residues and per Myr. Overall, mutation rate is double in titin (grey bars) with respect to myosin (white bars). Analysis of residue replacement and mutability for LTCA and human titin proximal (c) and distal (d) I-band, A-band (e) and myosin (f). For each residue type we estimate the occurrence in the different titin fragment as well as myosin for human and LTCA titin. The difference is the replacement for each residue type in the transition between LTCA and human titin. We thus estimate the ratio between replacement and relative mutability considering Ala as reference with a value of 100 (Dayhoff M.O. et al. Biomedical Research Foundation, Silver Spring: MD, 1978; Vol. 5. 3). In the plot this ratio is represented for each residue. A positive value (red bars) indicate an increasing number of the specific amino acid in the transition from LTCA to human. The blue bars represent a decreasing number of residues. Cysteine residues have decreased their representation in the I-band of human titin much more prominently than any other residue. In the contrary, these residues have increased their number in the A-band of titin and myosin.
