Fig. 4

Positively-charged patches and predicted stability in EPO orthologues. (a) A sequence-based phylogenetic tree is combined with positive patch and stability calculations. Colour coding for posQmax varies from lighter to darker blue as the calculated largest positive patch increases for an EPO orthologue (same colour code for histogram in panel b). Predicted pH-dependent contribution to folded state stability (pHstab) varies from yellow (positive, unfavourable) to green (negative, favourable). (b) Distribution of largest positive patch ratios to the threshold for the 115 EPO orthologues, showing that surface charge changes substantially. HuEPO is located roughly in the centre of the distribution. Frequency is the number of EPO orthologues having a largest positive patch ratio to threshold, in the given x-axis bin