Correlation between structure and sequence similarity in comparisons of the superfamilies analyzed in this study.

<p>The comparisons were performed in all cases between a non-propeller fold and the closest β-propeller superfamily, as deduced from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077074#pone-0077074-g002" target="_blank">Figure 2</a>. The panels show in orange: A) IRE1-LD vs. PQQ, B) β-prism type II vs. PQQ, C) β-pinwheels vs. WD40, and D) WW domains vs. PQQ. In each case, the comparison of the non-propeller fold to a background set of proteins consisting of the SCOP all-β class minus the superfamilies of this study is shown in blue as a reference (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077074#s2" target="_blank">Methods</a>). The plots represent the structure and sequence similarity of a pair of compared structures as a dot. The linear regression for each group of comparisons is shown as a dashed line, while the ellipses represent one, two, and three standard deviations around the mean.