Fig. 5
From: Crystallographic and spectroscopic assignment of the proton transfer pathway in [FeFe]-hydrogenases

Hydrogen-bonding pattern in the catalytic PT pathway of the Hox state. H-bond pattern of Hox according to pKa values of the residues calculated for the structure of wild-type CpI (4XDC19) via PROPKA41 (see red numbers in parentheses). The pKa of the adt-ligand in Hox is derived from a previous study58. The blue numbers indicate the distances between neighboring positions of the PT pathway. The arrow labeled “SB” indicates a presumptive salt bridge contact between R286 and deprotonated E282