EC Number   |
General Information |
Reference |
|---|
    1.8.99.5 | evolution |
MccA belongs to the genetically diverse family of multiheme c enzymes and has eight heme groups covalently attached to conserved heme-binding motifs in the peptide sequence. Multiheme cytochrome c enzymes show a high conservation of heme group arrangements, but not of sequence, with recurring heme-packing motifs that result in either a parallel or a perpendicular packing of two of the moieties. They catalyse complexmulti-electron redox reactions and bind their substrates through the free electron pairs of a heteroatom to a free coordination position at an active-site hem group. Electrons are then provided or accepted by the tightly coupled chain of heme groups |
743347 |
| 1.8.99.5 | metabolism |
DsrC is a key protein in dissimilatory sulfite reduction |
741814 |
| 1.8.99.5 | metabolism |
the enzyme encoded by MET5 is involved in the sulfur metabolic pathway in the sulfur assimilation of Cryptococcus neoformans, overview. Sulfate is used by the active MET3, MET14, MET5, and MET10 genes in the sulfate assimilation pathway |
-, 764536 |
| 1.8.99.5 | more |
anoxically purified MccA exhibits a 2 to 5.5fold higher specific sulfite reductase activity than the enzyme isolated under oxic conditions. Presence of two cysteine residues, C399 and C495, juxtaposed at the distal side of the active-site cavity. The active site is a shallow cavity on the distal side of heme 2, lined by residues K208, Y285, Y301, R366 and K393, which are conserved among MccA orthologues |
743347 |
| 1.8.99.5 | physiological function |
in salt marsh sediments exposed to acid mine drainage for over 100 years, recovered dsrAB sequences of dissimilatory sulfite redactase genes from three sites indicate the dominance of a single Desulfovibrio species. Other major sequence clades are related most closely to Desulfosarcina, Desulfococcus, Desulfobulbus, and Desulfosporosinus species. The presence of metal sulfides with low delta34S values relative to delta34S values of pore water sulfate show that sediment sulfate-reducing bacteria populations are actively reducing sulfate under ambient conditions (pH of about 2), although possibly within less acidic microenvironments. Findings imply a highly dynamic microbially mediated cycling of sulfate and sulfide, and thus the speciation and mobility of chalcophilic contaminant metal(loid)s in acid mine drainage-impacted marsh sediments |
710943 |
| 1.8.99.5 | physiological function |
polar insertion mutations immediately upstream of dsrA, and in dsrB, in the gene cluster dsrABEFHCMK lead to an inability of the cells to oxidize intracellularly stored sulfur. The capability of the mutants to oxidize sulfide, thiosulfate and sulfite under photolithoautotrophic conditions is unaltered. Photoorganoheterotrophic growth is also unaffected |
-, 734636 |
| 1.8.99.5 | physiological function |
sulfur globule oxidation is strictly dependent on the dissimilatory sulfite reductase system. Deletion of dsrM or dsrT, or the two dsrCABL clusters abolishes sulfur globule oxidation and prevents formation of sulfate from sulfide. The DSR system also seems to be involved in the formation of thiosulfate. The dsr mutants incapable of complete substrate oxidation oxidizes sulfide and thiosulfate about twice as fast as the wild-type, while having only slightly lower growth rates of 7080% of wild-type |
-, 725901 |
| 1.8.99.5 | physiological function |
the Epsilonproteobacterium Wolinella succinogenes does not encode a siroheme sulfite reductase and the nrfA gene is not induced during sulfite respiration. Instead, sulfite is reduced by the octaheme c-type cytochrome MccA, with sulfide as the sole product. The enzyme MccA catalyzes the six-electron reduction of sulfite to sulfide, the pivot point of the biogeochemical cycle of the element sulfur for dissimilatory sulfite utilization. It is distinct from known sulfite reductases because it has a substantially higher catalytic activity and a relatively low reactivity towards nitrite |
743347 |
| 1.8.99.5 | physiological function |
the QmoABC membrane complex is essential for efficient electron delivery to AprAB, in order to sustain catalysis. Direct electron transfer occurs AprAB and the QmoABC complex, coupling the quinone-pool to sulfate reduction |
741984 |
| 1.8.99.5 | physiological function |
the sulfite reductase MET5 gene confers Cys auxotrophy |
-, 764536 |
