Fig. 1.
(A) Overview of the structure of cytochrome cbb3 from P. stutzeri (16) with the CcoN, O, and P subunits (A, B, and C chains in PDB ID code 3MK7) in yellow, blue, and red, respectively. (B) An enlargement of the region around the equivalent of the K path for proton transfer with the residue under investigation in this study, the Glu(E)-49 (numbering is according to the P. stutzeri sequences, only the R. sphaeroides equivalent of Glu-49 (E-25) is indicated in parenthesis) of the CcoP subunit marked by a red circle. The figure was produced using the VMD software (47). For the numbers of the corresponding residues in R. sphaeroides cbb3, see Fig. S1.