>cd01661 cbb3_Oxidase_I Cytochrome cbb3 oxidase subunit I. Cytochrome cbb3 oxidase, the terminal oxidase in the respiratory chains of proteobacteria, is a multi-chain transmembrane protein located in the cell membrane. Like other cytochrome oxidases, it catalyzes the reduction of O2 and simultaneously pumps protons across the membrane. Found mainly in proteobacteria, cbb3 is believed to be a modern enzyme that has evolved independently to perform a specialized function in microaerobic energy metabolism. Subunit I contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme and a copper ion. It also contains a low-spin heme, believed to participate in the transfer of electrons to the binuclear center. The cbb3 operon contains four genes (ccoNOQP or fixNOQP), with ccoN coding for subunit I. Instead of a CuA-containing subunit II analogous to other cytochrome oxidases, cbb3 utilizes subunits ccoO and ccoP, which contain one and two

Probab=98.87 E-value=1e-05 Score=56.52 Aligned_cols=231 Identities=14% Similarity=0.133 Sum_probs=128.8 Q ss_pred HHHHHHHHHHHHHHHHHHHHHH-HHHHHHHHHHHCCCCCHHHHHHHHHHHH------HHHHHHHHHHHHCCCCCCCHHHH Q ss_conf 1322123334012579999879-9999999853105640266899999999------99997533221022478758899 Q gi|254780473|r 283 MMYINLIWIWGHPEVYILVLPA-FGIFSEVVATFSGKRLFGYNSMVYATLA------ITILSYTVWLHHFFTMGSGANVN 355 (671) Q Consensus 283 lL~q~LFW~fGHPeVYIliLPa-~Gi~seiip~fs~kplfgy~~~v~A~~~------i~~lsf~VW~HHmFt~G~~~~~~ 355 (671) T Consensus 84 ltfgrlr~~Htn~~ifgw~~~a~~g~a~ylvPr~~~t~l~~~~L~~~~fw~~~~g~~l~~~~~~~G~----t~g~E--y~ 157 (493) T cd01661 84 LSFGRLRPLHTNAVIFGFGGNALIATSFYVVQRTCRARLAGGNLAWFVFWGYNLFIVLAATGYLLGI----TQGKE--YA 157 (493) T ss_pred CCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCHHHHHHHHHHHHHHHHHHHHHHCCC----CCCCC--HH T ss_conf 1532126878899999999999999999999999598268752899999999999999999997358----79965--20 Q ss_pred HHHHHHHHHHHHHHHHHHHHHHHHHCCCCCE-ECHHHHHHHHHHHHHH----HHHHHHHHCCCCCCCEEEC------CCE Q ss_conf 8765334678898779999878742587302-2437999999999999----8875565303432111212------742 Q gi|254780473|r 356 AFFGIMTMVIAVPTGAKIFNWLFTMRLGKVR-FEVPMMWTLGFMITFL----IGGMTGVLLAVPPADFTLH------NSL 424 (671) Q Consensus 356 ~~F~i~Tm~IaIPTgvkiFnwl~Tl~~G~ir-~~~pml~~lgfi~~F~----iGG~tGv~lA~~~~D~~lH------nT~ 424 (671) T Consensus 158 E~pw~idi~i~v~~~~~~~~~~~Ti~~rr~~~iyvs~W~~la~li~~~~l~~~~~l~~~~~~~~~~~~~~~~Gv~~a~~~ 237 (493) T cd01661 158 EPEWYVDLWLTVVWVAYLLPFLGTLLRRKEPHIYVANWYYLAFIVTVAVLHIVNNLAVPVSWFGSKSYSAHAGVQDATTQ 237 (493) T ss_pred CCHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCEEHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCCCCHHHHHHH T ss_conf 25299999999999999999999999716996033699999999999999999887887887312313535342766888 Q ss_pred EHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCC-CHHHHHHHHHHHHH-HHHHHHHHHHHHHHHCCCHHHCCCCCCHHH Q ss_conf 2044789999999999999999996244307674-71689999999999-999999999998764053030025870057 Q gi|254780473|r 425 FLVAHFHNTIIGGVVFGLFAGIVYWFPKAFGYQL-NSFWGKVSFWCWFV-GFYLAFMPLYALGLKGVTRRLSQYEDTTLQ 502 (671) Q Consensus 425 fVVAHFHyvl~gg~vf~~fagiyyW~Pk~~Gr~l-~e~lgk~~Fwl~~i-Gf~l~F~pm~~lGl~GmpRR~~~y~~~~~~ 502 (671) T Consensus 238 Wwfg--H~~V~~~ltp~~lgi~yy~lPk~~~rPi~sy~l~vi~fwal~~~~~~~g--~HH~~----------~~~~P~w- 302 (493) T cd01661 238 WWYG--HNAVGFFLTAGFLAMMYYFLPKIAERPVYSYRLSIIGFWALAFLYIWAG--PHHLH----------YTALPDW- 302 (493) T ss_pred HHHH--CHHHHHHHHHHHHHHHHHHHHHHHCCCEEEEHHHHHHHHHHHHHHHHHH--HHHHH----------CCCCHHH- T ss_conf 7651--4289999999999999999999819862543299999999999999875--62730----------5780789- Q ss_pred HHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCC Q ss_conf 999999999999999999999999999744953 Q gi|254780473|r 503 VYYVVALLGAVLIGIGVFSFVLSFIVSFLNRSK 535 (671) Q Consensus 503 ~~n~istiGa~l~~~g~l~f~~nl~~S~~~~~~ 535 (671) T Consensus 303 -~~~~~~v~S~l~~vP~~~~~~N~~~Tl~g~w~ 334 (493) T cd01661 303 -LQTLGMVFSVMLWMPSWAGMINGLLTLRGAWD 334 (493) T ss_pred -HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHC T ss_conf -99999999999999899999999999984212

HHsearch alignment for GI: 254780473 and conserved domain: cd01661