Hydrogen Sulfide: A Toxic Gas Produced by Dissimilatory Sulfate and Sulfur Reduction and Consumed by Microbial Oxidation - The Metal-Driven Biogeochemistry of Gaseous Compounds in the Environment - page 260

Figure 5 Model of sulfur-reducing complexes in membranes of A. ambivalens and
W. succinogenes . PsrABC are sulfur-reducing subunits and HynABC are hydrogenase subunits
of W. succinogenes .MK ¼ menaquinone, SreABC are sulfur-reducing subunits and HynL, HynS,
and Isp1 are hydrogenase subunits of A. ambivalens ,SQ ¼ sulfolobusquinone, X ¼ [4Fe-4S]
center, 2e ¼ 2 electrons, and dashed lines indicates electron flow. The two vertical red lines in
HynC and Isp1 indicate the presence of two b-type hemes. Out ¼ periplasm and In ¼ cytoplasm.
Reproduced by permission from [ 25 ]; copyright 2012, Academic Press.