>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=91.39 E-value=0.62 Score=26.30 Aligned_cols=142 Identities=15% Similarity=0.311 Sum_probs=91.0 Q ss_pred CHHHHHHHHHHHHHCCCCEEEEEEECCEEC----------CC--CC--CCHHHHHHHHH---CCCCEEEEEEEEEECCHH Q ss_conf 889999999999965998999973426345----------84--34--17899998641---256416856788512033 Q gi|254780975|r 15 DFSRLGEEISNITKAGAKQIHFDVMDGCFV----------PN--IS--FGADVIRSLRS---YSDSVFDCHLMISSIDSH 77 (224) Q Consensus 15 d~~~l~~~i~~l~~~~~d~iHiDImDg~fv----------pn--~~--~~~~~i~~i~~---~t~~~~dvHLMv~~P~~~ 77 (224) T Consensus 147 DLA~v-aHlAtl-earVPF~HF--FDGFRTSHEIQKIE~ldye~~a~lvn~e~v~~fR~r~lnPe~P-~vRGTaQNPDIY 221 (1194) T TIGR02176 147 DLALV-AHLATL-EARVPFMHF--FDGFRTSHEIQKIEVLDYEDLASLVNDELVKAFRKRSLNPEHP-EVRGTAQNPDIY 221 (1194) T ss_pred HHHHH-HHHHHH-HHCCCCCCC--CCCCCCCCHHHHHEECCHHHHHHCCCHHHHHHHHHHCCCCCCC-EEECCCCCCCCC T ss_conf 78999-999998-616874125--7876322011111022758651016988999997416688877-540346587712 Q ss_pred ---------------------HHHHCCC--------------CCCEEEEECCCCC-CHHHHHHHHHHCCCEEEEE-EECC Q ss_conf ---------------------6764047--------------7607999706642-1589998677649825998-5233 Q gi|254780975|r 78 ---------------------INIIADA--------------GCDIITFHPESSP-HIRRSLRTIHAMGKKTGVA-INPE 120 (224) Q Consensus 78 ---------------------i~~~~~~--------------g~d~i~~H~E~~~-~~~~~i~~i~~~g~k~Gia-i~p~ 120 (224) T Consensus 222 FQ~REa~N~YY~a~P~IVq~yM~~~a~lTGR~Y~LfdYYGapdAE~vIi~MGSvaeTieEtvdyL~~kG~KvGllkVrLY 301 (1194) T TIGR02176 222 FQGREAVNKYYEAVPEIVQKYMDKIAKLTGRSYHLFDYYGAPDAERVIIAMGSVAETIEETVDYLRSKGEKVGLLKVRLY 301 (1194) T ss_pred CCCCCCCCCHHHCCCHHHHHHHHHHHHCCCCCCCCCCCCCCCCCCCEEEECCCHHHHHHHHHHHHHHCCCEEEEEEEEEC T ss_conf 04541437121013358999998876305765675233787020310440585667899999999728932768887512 Q ss_pred CCH--HHHHHHHHH-CCEEEEE--EEECCCCCCCCCCHHHHHHHHH Q ss_conf 344--789988620-1402899--8306776533220135778998 Q gi|254780975|r 121 TPV--AILEDVIDE-IDMILIM--TVNPGFGGQQLIESTIPKIRQA 161 (224) Q Consensus 121 T~~--~~i~~~l~~-~D~vliM--~V~PG~~Gq~f~~~~l~kI~~l 161 (224) T Consensus 302 RPF~~~~F~~~lP~svK~IAVLDRtKEPGa~GEPLYLDV~~A~~e~ 347 (1194) T TIGR02176 302 RPFSAETFLAALPKSVKRIAVLDRTKEPGAAGEPLYLDVRSAFYEM 347 (1194) T ss_pred CCCCHHHHHHHCCCCCCEEEEECCCCCCCCCCCCHHHHHHHHHHCC T ss_conf 7985899998424110122212355688655684488899886304

HHsearch alignment for GI: 254780975 and conserved domain: TIGR02176