RPSBLAST alignment for GI: 254780473 and conserved domain: cd00919

>gnl|CDD|29930 cd00919, Heme_Cu_Oxidase_I, Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in the respiratory chains of prokaryotes and mitochondria which catalyze the reduction of O2 and simultaneously pump protons across the membrane. The superfamily is diverse in terms of electron donors, subunit composition, and heme types. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. It has been proposed that Archaea acquired heme-copper oxidases through gene transfer from Gram-positive bacteria. Membership in the superfamily is defined by subunit I, which 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. Only subunit I is common to the entire superfamily. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from the electron donor on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I of cytochrome c oxidase (CcO) and ubiquinol oxidase. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electron transfer occurs in two segments: from the electron donor to the low-spin heme, and from the low-spin heme to the binuclear center. The first segment can be a multi-step process and varies among the different families, while the second segment, a direct transfer, is consistent throughout the superfamily.. Length = 463
 Score =  452 bits (1165), Expect = e-127
 Identities = 229/467 (49%), Positives = 315/467 (67%), Gaps = 4/467 (0%)

Query: 64  HKKIGIMYIILSLVMLFRGFADAIMMRLQQAIASGGGEGYLDAHHYDQIFTAHGVIMIFF 123
           HK IG++Y+I + V L  G   A+++RL+ A     G  +LD   Y+Q+ TAHGVIMIFF
Sbjct: 1   HKDIGLLYLIFAFVALLLGGLLALLIRLELATP---GSLFLDPQLYNQLVTAHGVIMIFF 57

Query: 124 VAMPMITGIMNFVVPLQIGARDVSFPFLNNFSFWMTVAGAVVIMCSLFIGEFASVGWLAY 183
             MP I G    ++P  IGARD++FP LNN SFW+   G ++++ S+ +G  A  GW  Y
Sbjct: 58  FVMPAIFGGFGNLLPPLIGARDLAFPRLNNLSFWLFPPGLLLLLSSVLVGGGAGTGWTFY 117

Query: 184 PPLSGISYSPGVGVDYYIWGLQIAGIGTTLSGINLVVTIIKMRCPGMTMMKMPVFVWTAF 243
           PPLS +SYS GVGVD  I GL +AG+ + L  IN + TI+ MR PGMT+ KMP+FVW+  
Sbjct: 118 PPLSTLSYSSGVGVDLAILGLHLAGVSSILGAINFITTILNMRAPGMTLDKMPLFVWSVL 177

Query: 244 CSNIMIIAAFPILTATLFLLTLDRYIGTNFFTNHLGGNPMMYINLIWIWGHPEVYILVLP 303
            + I+++ A P+L A L +L LDR  GT+FF    GG+P++Y +L W +GHPEVYIL+LP
Sbjct: 178 VTAILLLLALPVLAAALVMLLLDRNFGTSFFDPAGGGDPVLYQHLFWFFGHPEVYILILP 237

Query: 304 AFGIFSEVVATFSGKRLFGYNSMVYATLAITILSYTVWLHHFFTMGSGANVNAFFGIMTM 363
           AFG  SE++ TFSGK LFGY  MVYA LAI  LS+ VW HH FT+G   +  A+F   TM
Sbjct: 238 AFGAISEIIPTFSGKPLFGYKLMVYAFLAIGFLSFLVWAHHMFTVGLPVDTRAYFTAATM 297

Query: 364 VIAVPTGAKIFNWLFTMRLGKVRFEVPMMWTLGFMITFLIGGMTGVLLAVPPADFTLHNS 423
           +IAVPTG K+FNWL T+  G++RF+ PM++ LGF+  F IGG+TGV+LA  P D  LH++
Sbjct: 298 IIAVPTGIKVFNWLATLWGGRIRFDPPMLFALGFLFLFTIGGLTGVVLANVPLDIVLHDT 357

Query: 424 LFLVAHFHNTIIGGVVFGLFAGIVYWFPKAFGYQLNSFWGKVSFWCWFVGFYLAFMPLYA 483
            ++VAHFH  + GGVVF +FAG+ YWFPK  G  L+   GK+ FW WF+GF L F P++ 
Sbjct: 358 YYVVAHFHYVLSGGVVFAIFAGLYYWFPKMTGRMLSEKLGKIHFWLWFIGFNLTFFPMHF 417

Query: 484 LGLKGVTRRLSQYEDTTLQVYYVVALLGAVLIGIGVFSFVLSFIVSF 530
           LGL G+ RR + Y D     +  ++ +GA ++G+G+  F+ +  +S 
Sbjct: 418 LGLLGMPRRYADYPD-GFAPWNFISSVGAFILGLGLLLFLGNLFLSL 463