A plot of entropy versus optimal sequence residue. Bars in orange show the mean relative entropy for each of the 20 amino acids. Entropy is shown on log scale. Amino acid type for each residue position was determined from the optimal sequences generated from the PSI-BLAST profiles and came from searches of the Combined-nr. The bar marked "WW" refers to tryptophans in repeats. The purple line shows the variance of the relative entropy. Positions with repeat tryptophans clearly have the lowest mean entropy and the lowest variance.