| [A] Metallosphaera sedula (strain ATCC 51363 / DSM 5348) | METS500673 | A4YEJ8 | Succinate dehydrogenase subunit C |
| [A] Sulfolobus acidocaldarius | SULAC00909 | P77945 | succinate dehydrogenase subunit C |
| [A] Sulfolobus islandicus (strain L.S.2.15 / Lassen #1) | SULIL00189 | C3MK45 | |
| [A] Sulfolobus islandicus (strain M.14.25 / Kamchatka #1) | SULIM00156 | C3MU14 | |
| [A] Sulfolobus islandicus (strain M.16.27) | SULIA00157 | C3N0M6 | |
| [A] Sulfolobus islandicus (strain Y.G.57.14 / Yellowstone #1) | SULIY00160 | C3N8L4 | |
| [A] Sulfolobus islandicus (strain Y.N.15.51 / Yellowstone #2) | SULIN02419 | C3NM83 | |
| [A] Sulfolobus solfataricus | SULSO02104 | Q97W77 | Succinate dehydrogenase subunit C |
| [A] Sulfolobus tokodaii | SULTO00550 | Q9C4L7 | hypothetical succinate dehydrogenase subunit C |
| [A] Archaeoglobus fulgidus | ARCFU01348 | O28896 | Heterodisulfide reductase, subunit B |
| [A] Methanobrevibacter smithii (strain PS / ATCC 35061 / DSM 861) | METS300786 | A5ULC2 | Heterodisulfide reductase, subunit B, HdrB |
| [A] Methanosphaera stadtmanae (strain DSM 3091) | METST00977 | Q2NFK2 | HdrB1 heterodisulfide reductase, subunit B1 |
| [A] Methanobacterium thermoautotrophicum | METTH01835 | HDRB_METTH | CoB--CoM heterodisulfide reductase subunit B |
| [A] Methanocaldococcus jannaschii | METJA00891 | HDRB2_METJA | CoB--CoM heterodisulfide reductase subunit B 2 |
| [A] Methanococcus maripaludis | METMP01053 | Q6LYD8 | Heterodisulfide reductase; subunit B2 |
| [A] Methanococcus maripaludis (strain C5 / ATCC BAA-1333) | METM500536 | A4FXC5 | CoB--CoM heterodisulfide reductase |
| [A] Methanococcus maripaludis (strain C6 / ATCC BAA-1332) | METM601590 | A9AAP4 | CoB--CoM heterodisulfide reductase, subunit B |
| [A] Methanococcus maripaludis (strain C7 / ATCC BAA-1331) | METM700304 | A6VG01 | CoB--CoM heterodisulfide reductase |
| [A] Methanococcus vannielii (strain SB / ATCC 35089 / DSM 1224) | METVS00367 | A6UP63 | CoB--CoM heterodisulfide reductase |
| [A] Methanoregula boonei (strain 6A8) | METB600583 | A7I5U6 | CoB--CoM heterodisulfide reductase |
| [A] Methanocorpusculum labreanum (strain ATCC 43576 / DSM 4855 / Z) | METLZ00238 | A2SQ10 | Hypothetical protein |
| [A] Methanoculleus marisnigri (strain ATCC 35101 / DSM 1498 / JR1) | METMJ00609 | A3CT57 | CoB--CoM heterodisulfide reductase |
| [A] Methanosphaerula palustris (strain ATCC BAA-1556 / DSM 19958 / E1-9c) | METPE02137 | B8GE32 | CoB/CoM heterodisulfide reductase, subunit B |
| [A] Methanospirillum hungatei (strain JF-1 / DSM 864) | METHJ01737 | Q2FKZ2 | protein of unknown function DUF224, cysteine-rich region |
| [A] Methanococcoides burtonii (strain DSM 6242) | METBU01377 | Q12VV2 | Hypothetical protein |
| [A] Methanosarcina acetivorans | METAC04051 | HDRB_METAC | CoB--CoM heterodisulfide reductase 1 subunit B |
| [A] Methanosarcina barkeri (strain Fusaro / DSM 804) | METBF00616 | Q46ES4 | heterodisulfide reductase, subunit B |
| [A] Methanosarcina mazei | METMA00966 | HDRB_METMA | CoB--CoM heterodisulfide reductase 1 subunit B |
| [A] Methanopyrus kandleri | METKA00572 | HDRB_METKA | CoB--CoM heterodisulfide reductase subunit B |
| [A] Picrophilus torridus | PICTO00997 | Q6L0C0 | Succinate dehydrogenase, subunit C |
| [A] Uncultured methanogenic archaeon RC-I | UNCMA00269 | Q0W0U7 | heterodisulfide reductase, subunit B |
| [B] Chlorobium chlorochromatii (strain CaD3) | CHLCH00127 | Q3AUB8 | succinate/fumarate oxidoreductase, putative |
| [B] Chlorobium limicola (strain DSM 245 / NBRC 103803) | CHLL202242 | B3EHV6 | CoB--CoM heterodisulfide reductase |
| [B] Chlorobium phaeobacteroides (strain BS1) | CHLPB00262 | B3EL28 | CoB--CoM heterodisulfide reductase |
| [B] Chloroherpeton thalassium (strain ATCC 35110 / GB-78) | CHLT300161 | B3QSZ0 | CoB--CoM heterodisulfide reductase |
| [B] Acaryochloris marina (strain MBIC 11017) | ACAM105266 | B0CE06 | Heterodisulfide reductase, subunit B, putative |
| [B] Cyanothece sp. (strain PCC 7425 / ATCC 29141) | CYAP402251 | B8HY80 | CoB--CoM heterodisulfide reductase |
| [B] Gloeobacter violaceus | GLOVI02933 | Q7NCN3 | succinate dehydrogenase chain C |
| [B] Microcystis aeruginosa (strain NIES-843) | MICAN04247 | B0JTT0 | Heterodisulfide reductase subunit B |
| [B] Synechococcus sp. (strain ATCC 27264 / PCC 7002 / PR-6) | SYNP200821 | B1XIG8 | Heterodisulfide reductase, subunit B |
| [B] Thermosynechococcus elongatus (strain BP-1) | THEEB00957 | Q8DK87 | Succinate dehydrogenase subunit C |
| [B] Anabaena variabilis (strain ATCC 29413 / PCC 7937) | ANAVT03576 | Q3M6Y2 | Protein of unknown function DUF224, cysteine-rich region |
| [B] Anabaena sp. (strain PCC 7120) | ANASP03309 | Q8YRV1 | Heterodisulfide reductase, subunit B |
| [B] Nostoc punctiforme (strain ATCC 29133 / PCC 73102) | NOSP704037 | B2IWR5 | Putative uncharacterized protein |
| [B] Trichodesmium erythraeum (strain IMS101) | TRIEI00364 | Q119B2 | Hypothetical protein |
| [B] Geobacter metallireducens (strain GS-15 / ATCC 53774 / DSM 7210) | GEOMG00296 | Q39YW9 | protein of unknown function DUF224, cysteine-rich region |
| [B] Campylobacter concisus (strain 13826) | CAMC101001 | A7ZDK9 | Succinate dehydrogenase, subunit C |
| [B] Campylobacter jejuni | CAMJE00408 | A3YJ23 | Putative succinate dehydrogenase subunit C |
| [B] Campylobacter jejuni (strain RM1221) | CAMJR00480 | Q5HW26 | identified by similarity to GP:3378542; match to protein family HMM PF02754 succinate dehydrogenase, C subunit |
| [B] Campylobacter jejuni subsp. jejuni serotype O:23/36 (strain 81-176) | CAMJJ00426 | A1VYF6 | succinate dehydrogenase, C subunit identified by match to protein family HMM PF02754 |
| [B] Campylobacter jejuni subsp. jejuni serotype O:6 (strain 81116 / NCTC 11828) | CAMJ800412 | A8FKM6 | Putative succinate dehydrogenase subunit C |
| [B] Sulfurimonas denitrificans (strain ATCC 33889 / DSM 1251) | SULDN01011 | Q30RS5 | Succinate dehydrogenase subunit C |
| [B] Wolinella succinogenes | WOLSU01739 | Q7M825 | SUCCINATE DEHYDROGENASE SUBUNIT C |
| [B] Nautilia profundicola (strain ATCC BAA-1463 / DSM 18972 / AmH) | NAUPA01008 | B9L9Z2 | CoB--CoM heterodisulfide reductase subunit B |
| [B] Nitratiruptor sp. (strain SB155-2) | NITSB00688 | A6Q2U3 | Succinate dehydrogenase/fumarate reductase, subunit C |
| [B] Sulfurovum sp. (strain NBC37-1) | SULNB01199 | A6Q9J8 | Succinate dehydrogenase/fumarate reductase, subunit C |
| [B] Magnetococcus sp. (strain MC-1) | MAGSM00415 | A0L4R1 | CoB--CoM heterodisulfide reductase PFAM: protein of unknown function DUF224, cysteine-rich region domain protein KEGG: chy:CHY_0065 putative succinate/fumarate oxidoreductase |