Figure 5From: Comparable contributions of structural-functional constraints and expression level to the rate of protein sequence evolutionDifferences of evolution rates for domains contained in the same multidomain protein and in different proteins, compared to randomized "domain" sequences from multidomain proteins. X-axis: log10 of the ratio of evolution rates of a pair of domains. Y-axis: probability density function. Red, domain pairs within multidomain proteins; black, all possible pairwise combinations of the same domains (from both multidomain proteins and proteins in which the respective domains occur separately); green, randomized domains within multidomain proteins (control for sampling error). The randomized domains were obtained by randomly shuffling the columns in a multidomain protein alignment, and evolution rates were calculated for regions within the original domain boundaries. V a , V m , and V r are the normalized variances of the distributions for all domain pairs, domain pairs within multidomain proteins, and randomized domains, respectively. A – Human proteins: V a /V m /V r = 9.57/1.00/0.40. B – Arabidopsis proteins: V a /V m /V r = 6.14/1.00/0.22.Back to article page