>TIGR02176 pyruv_ox_red pyruvate:ferredoxin (flavodoxin) oxidoreductase; InterPro: IPR011895 The oxidative decarboxylation of pyruvate to acetyl-CoA, a central step in energy metabolism, can occur by two different mechanisms . In mitochondria and aerobic bacteria this reaction is catalysed by the multienzyme complex pyruvate dehydrogenase using NAD as electron acceptor. In anaerobic organisms, however, this reaction is reversibly catalysed by a single enzyme using either ferrodoxin or flavodoxin as the electron acceptor. Pyruvate:ferrodoxin/flavodoxin reductases (PFORs) in this entry occur in both obligately and facultatively anaerobic bacteria and also some eukaryotic microorganisms. These proteins are single-chain enzymes containing a thiamin pyrophosphate cofactor for the cleavage of carbon-carbon bonds next to a carbonyl group, and iron-sulphur clusters for electron transfer. The Desulfovibrio africanus enzyme is currently the only PFOR whose three dimensional structure is known , . It is a homodimer where each subunit contains one thiamin pyrophosphate cofactor and two ferrodoxin-like 4Fe-S clusters and an atypical 4Fe-S cluster. Each monomer is composed of seven domains - domains I, II and VI make intersubunit contacts, while domains III, IV and V are located at the suface of the dimer, and domain VII forms a long arm extending over the other subunit. The cofactor is bound at the interface of domains I and VI and is proximal to the atypical 4Fe-S bound by domain VI, while the ferrodoxin-like 4Fe-S clusters are bound by domain V. Comparison of this enzyme with the multi-chain PFORs shows a correspondance between the domains in this enzyme and the subunits of the multi-chain enzymes.; GO: 0005506 iron ion binding, 0016903 oxidoreductase activity acting on the aldehyde or oxo group of donors, 0006118 electron transport.

Probab=97.56  E-value=5.1e-06  Score=57.68  Aligned_cols=68  Identities=18%  Similarity=0.388  Sum_probs=36.7

Q ss_pred             HHHHHHHHHCCCHHHCCCEE-----ECCCCC-CCHHHHHHHHHHHCCCCCCC-HHHHHHHHCCCCCCCCCCCCCCHHHHC
Q ss_conf             66888887313132282001-----022210-11478899988516888431-388999622866527676647345518
Q gi|254781044|r  165 DGLYECVMCACCSTSCPSYW-----WNSDRY-LGPAILLQAYRWLIDSRDEF-QGERLDNLEDPFRLYRCHTIMNCTQSC  237 (259)
Q Consensus       165 ~~~~~CI~CG~C~saCP~~~-----~~~~~f-lGP~~l~~a~r~~~D~rD~~-~~erl~~l~~~~gi~~C~~C~~C~~vC  237 (259)
T Consensus       696 W~~d~CiqCnqCa~VCPHaaIR~~l~~~ee~~~AP~~F~-----~~d~kGK~~~g~kyrIQvs---~~DCtGCglCvd~C  767 (1194)
T TIGR02176       696 WKSDNCIQCNQCAFVCPHAAIRPFLLDEEELEKAPEGFK-----SLDAKGKELEGLKYRIQVS---VEDCTGCGLCVDIC  767 (1194)
T ss_pred             CCCCCCCCCCCCCCCCCHHHHHHHHCCCHHHHCCCCCCE-----EECCCCCCCCCCCEEEEEC---CCCCCCCCCCCCCC
T ss_conf             565665347885433764787776427157635898647-----7134367889870068742---75035763420358


Q ss_pred             CCC
Q ss_conf             997
Q gi|254781044|r  238 PKG  240 (259)
Q Consensus       238 Pkg  240 (259)
T Consensus       768 Pa~  770 (1194)
T TIGR02176       768 PAK  770 (1194)
T ss_pred             CCC
T ss_conf             588