Figure 3
From: Graphical analysis of pH-dependent properties of proteins predicted using PROPKA
Comparative study of active site residues. By comparing pKa values of catalytic glutamic acids 172 and 177 together with their determinants, in two homologous xylanase structures [PDB:1XNB] and [PDB:1XYP], respectively, we find that the higher pKa of the former is mainly due to an extra charge-charge interaction with the glutamic acid 78.