Distributions of evolutionary rate difference of protein pairs within the age-homogeneous motifs and the other motifs. The probability (y-axis) is calculated as the percentage of protein pairs whose evolutionary rate difference falls in a special interval that x-axis shows. (A) 3-motif. Average evolutionary rate difference is 5.8 × 10-2 for 3-motifs whose constituents are of the same age class and 7.9 × 10-2 for the other 3-motifs. Rank sum test, P <10-4 . (B) 4-motif. The average evolutionary rate difference is 6.0 × 10-2 and 8.0 × 10-2 for the two 4-motif classes. Rank sum test, P <10-4 . The common protein pairs of the two motif classes are removed in the analyses. The results are based on the PIN of DIP_YEAST_CORE.
Liu et al. BMC Evolutionary Biology 2011 11:133 doi:10.1186/1471-2148-11-133