1.8.7.1 Fe-S center - 726232 1.8.7.1 Fe-S center the enzyme contains a [4Fe-4S]2+/1+ cluster and a siroheme active site 764195 1.8.7.1 Ferredoxin - 437707, 696126 1.8.7.1 Ferredoxin the enzyme can use its endogenous ferredoxin as well as the ferredoxin pssm2-Fd from its parasite myovirus P-SSM2. pssm2-Fd contains sequence features of host Fds, structure of the pssm2-Fd and structure comparisons, overview. Prochlorococcus marinus ferredoxin contains [4Fe-4S] centers, the myoviral ferredoxin contains [2Fe-2S] centers 765063 1.8.7.1 FMN - 657926 1.8.7.1 iron-sulfur centre - 696126 1.8.7.1 methyl viologen artificial cofactor 764195 1.8.7.1 additional information when expressed in an Escherichia coli strain deficient in sulfite assimilation, pssm2-Fd complements bacterial growth when coexpressed with a Prochlorococcus marinus sulfite reductase, revealing that pssm2-Fd can transfer electrons to a host protein involved in nutrient assimilation. The high levels of structural similarity with cyanobacterial Fds and reactivity with a host sulfite reductase suggest that phage Fds evolved to transfer electrons to cyanobacterially encoded oxidoreductases. The phage Fds all localize to cluster VI, in close association with cyanobacterial Fds. Among the Fds in cluster VI, interactions with a range of oxidoreductases have been documented. Evaluation of the surface charge distribution of several different Fd and SIR structures 765063 1.8.7.1 siroheme - 437687, 437688, 437689, 437690, 437702, 437703, 437704, 674459, 674525, 696126, 726232 1.8.7.1 siroheme 1 mol per mol subunit, in the high-spin Fe3+ state in the reduced enzyme 437695