1.8.7.1 hydrogen sulfide + 6 oxidized ferredoxin [iron-sulfur] cluster + 3 H2O - 1.8.7.1 hydrogen sulfide + oxidized ferredoxin + H2O - 1.8.7.1 sulfite + 3 FMNH2 sulfate assimilation pathway leading to the biosynthesis of organic sulfur compounds 1.8.7.1 sulfite + reduced ferredoxin - 1.8.7.1 sulfite + reduced ferredoxin assimilatory sulfate reduction 1.8.7.1 sulfite + reduced ferredoxin + 6 H+ sulfur assimilation for cysteine and methionine biosynthesis 1.8.7.1 sulfite + reduced ferredoxin + H+ -