>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=93.20  E-value=0.41  Score=27.35  Aligned_cols=91  Identities=18%  Similarity=0.300  Sum_probs=69.2

Q ss_pred             CCEEEEHHHHHHHHHHHHHHHHCCCCCEEEEECCCCCCCCHHHHHHHHHHCCCEE-EEECCCCCCCHHHHHHHHHHHHHH
Q ss_conf             7458602578888888875310046752797330068579999999998719899-995788767678999999999677
Q gi|254780673|r  340 DVTIISFGIGMTYATKAAIELEKNGIDAELIDLRTIRPMDWQTIFESVKKTGRLV-TVEEGYPQSSVGSTIANQVQRKVF  418 (467)
Q Consensus       340 ditii~~G~~~~~a~~aa~~L~~~gi~~~vid~r~l~Pld~~~i~~sv~kt~~~i-~vee~~~~gg~g~~i~~~i~e~~f  418 (467)
T Consensus       266 E~vIi~MGSvaeTieEtvdyL~~kG~KvGllkVrLYRPF~~~~F~~~lP~svK~IAVLDRtKEPGa~GEPLYLDV~-~A~  344 (1194)
T TIGR02176       266 ERVIIAMGSVAETIEETVDYLRSKGEKVGLLKVRLYRPFSAETFLAALPKSVKRIAVLDRTKEPGAAGEPLYLDVR-SAF  344 (1194)
T ss_pred             CCEEEECCCHHHHHHHHHHHHHHCCCEEEEEEEEECCCCCHHHHHHHCCCCCCEEEEECCCCCCCCCCCCHHHHHH-HHH
T ss_conf             3104405856678999999997289327688875127985899998424110122212355688655684488899-886


Q ss_pred             HHC--------CCCCEEECCC
Q ss_conf             642--------8982997177
Q gi|254780673|r  419 DYL--------DAPILTITGR  431 (467)
Q Consensus       419 ~~L--------~~p~~ri~~~  431 (467)
T Consensus       345 ~e~~~~~KCPf~~~P~I~GGR  365 (1194)
T TIGR02176       345 YEMQAEKKCPFESMPVIVGGR  365 (1194)
T ss_pred             HCCCCCCCCCCCCCCEEEEEE
T ss_conf             304001688865678588630