RPSBLAST alignment for GI: 254780290 and conserved domain: cd08253

>gnl|CDD|176215 cd08253, zeta_crystallin, Zeta-crystallin with NADP-dependent quinone reductase activity (QOR). Zeta-crystallin is a eye lens protein with NADP-dependent quinone reductase activity (QOR). It has been cited as a structural component in mammalian eyes, but also has homology to quinone reductases in unrelated species. QOR catalyzes the conversion of a quinone and NAD(P)H to a hydroquinone and NAD(P+. Quinones are cyclic diones derived from aromatic compounds. Membrane bound QOR acts in the respiratory chains of bacteria and mitochondria, while soluble QOR acts to protect from toxic quinones (e.g. DT-diaphorase) or as a soluble eye-lens protein in some vertebrates (e.g. zeta-crystalin). QOR reduces quinones through a semi-quinone intermediate via a NAD(P)H-dependent single electron transfer. QOR is a member of the medium chain dehydrogenase/reductase family, but lacks the zinc-binding sites of the prototypical alcohol dehydrogenases of this group. Alcohol dehydrogenase in the liver converts ethanol and NAD+ to acetaldehyde and NADH, while in yeast and some other microorganisms ADH catalyzes the conversion acetaldehyde to ethanol in alcoholic fermentation. ADH is a member of the medium chain alcohol dehydrogenase family (MDR), which has a NAD(P)(H)-binding domain in a Rossmann fold of a beta-alpha form. The NAD(H)-binding region is comprised of 2 structurally similar halves, each of which contacts a mononucleotide. The N-terminal catalytic domain has a distant homology to GroES. These proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and have 2 tightly bound zinc atoms per subunit, a catalytic zinc at the active site, and a structural zinc in a lobe of the catalytic domain. NAD(H)-binding occurs in the cleft between the catalytic and coenzyme-binding domains at the active site, and coenzyme binding induces a conformational closing of this cleft. Coenzyme binding typically precedes and contributes to substrate binding. In human ADH catalysis, the zinc ion helps coordinate the alcohol, followed by deprotonation of a histidine, the ribose of NAD, a serine, then the alcohol, which allows the transfer of a hydride to NAD+, creating NADH and a zinc-bound aldehyde or ketone. In yeast and some bacteria, the active site zinc binds an aldehyde, polarizing it, and leading to the reverse reaction. Length = 325
 Score =  222 bits (568), Expect = 1e-58
 Identities = 103/332 (31%), Positives = 164/332 (49%), Gaps = 13/332 (3%)

Query: 7   MRHVAMSGYGKSNVMFLAESPIPQPQKEEILIKVEAIGVNRPDVMQRKGLYPPPKNANPI 66
           MR +    +G  +V+ L + P+P P   E+L++V A GVN  D   R G YP       +
Sbjct: 1   MRAIRYHEFGAPDVLRLGDLPVPTPGPGEVLVRVHASGVNPVDTYIRAGAYPGLPPLPYV 60

Query: 67  LGLEVAGKIVDLGENTTHWNIGDEVCALVNG------GGYAEYCLSHQGHTLPIPKGYNA 120
            G + AG +  +GE      +GD V  L N       G  AEY +      +P+P G + 
Sbjct: 61  PGSDGAGVVEAVGEGVDGLKVGDRV-WLTNLGWGRRQGTAAEYVVVPADQLVPLPDGVSF 119

Query: 121 IQAASLPESFFTVWANLFQTANLRSGQTVLIHGGSSGIGTTAIQLASYFGATVYTTAKSE 180
            Q A+L     T +  LF  A  ++G+TVL+HGGS  +G  A+QLA + GA V  TA S 
Sbjct: 120 EQGAALGIPALTAYRALFHRAGAKAGETVLVHGGSGAVGHAAVQLARWAGARVIATASSA 179

Query: 181 EKCLACLKLGAKHAINYLKEDFLEILQKETQGRGIDIILDMVGAEYLNQHLTLLSKEGKL 240
           E      + GA    NY  ED  + +   T G+G+D+I++++    L + L +L+  G++
Sbjct: 180 EGAELVRQAGADAVFNYRAEDLADRILAATAGQGVDVIIEVLANVNLAKDLDVLAPGGRI 239

Query: 241 IIISFLGGNIATEINLNPIISKRITITGSTLRRRTDIAKQSIRDSLQLKIWPLLNSHVIA 300
           ++     G +   I +NP+++K  +I G  L   T   + +  +++       L    + 
Sbjct: 240 VVYG--SGGLRGTIPINPLMAKEASIRGVLLYTATPEERAAAAEAIA----AGLADGALR 293

Query: 301 PVIHTVLPLGKVAMAHDIMEKSEHIGKIILLP 332
           PVI    PL + A AH+ +E    IGK++L P
Sbjct: 294 PVIAREYPLEEAAAAHEAVESGGAIGKVVLDP 325