Fig. 3

Mutated residues on the surface of HuEPO. Molecular surface is shown (orange), with positive electrostatic field contoured at 30 mV (blue mesh). Residues E13 (red), F48 (grey) and R150 (blue) are shown in sticks, rather than surface representation. Also drawn are the non-polar residues V46 and L155 that are covered by F48 in the WT structure