TABLE 5.

Components of the electron transport system of N. pharaonis^a

Protein	Localization	Mr (103)	Cofactor(s)	E0 (mV)
Ferredoxin	Cytosol	15.2	2Fe-2S	−342
SDH complex	Membrane	90	FAD, FeS, heme B	+8 (FAD)
cyt c	Cytosol	75	Heme C	−142
cyt bc	Membrane	14, 18	Heme B, heme C	−117, −44
Halocyanine	Membrane	15.4	Cu	+128
cyt ba3	Membrane	40, 36	Heme B, heme AS, CuA, CuB	+268, +358

^aData was compiled from references 349, 350, 473, and 477, which describe all experimental details on electrochemistry and UV-visible spectroscopic data of solubilized or membrane-residing components. The redox potentials were determined at pH 8.