RPSBLAST alignment for GI: 254780290 and conserved domain: cd05195

>gnl|CDD|176179 cd05195, enoyl_red, enoyl reductase of polyketide synthase. Putative enoyl reductase of polyketide synthase. Polyketide synthases produce polyketides in step by step mechanism that is similar to fatty acid synthesis. Enoyl reductase reduces a double to single bond. Erythromycin is one example of a polyketide generated by 3 complex enzymes (megasynthases). 2-enoyl thioester reductase (ETR) catalyzes the NADPH-dependent dependent conversion of trans-2-enoyl acyl carrier protein/coenzyme A (ACP/CoA) to acyl-(ACP/CoA) in fatty acid synthesis. 2-enoyl thioester reductase activity has been linked in Candida tropicalis as essential in maintaining mitiochondrial respiratory function. This ETR family is a part of the medium chain dehydrogenase/reductase family, but lack the zinc coordination sites characteristic of the alcohol dehydrogenases in this family. NAD(P)(H)-dependent oxidoreductases are the major enzymes in the interconversion of alcohols and aldehydes or ketones. 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. Length = 293
 Score =  186 bits (475), Expect = 7e-48
 Identities = 87/315 (27%), Positives = 149/315 (47%), Gaps = 42/315 (13%)

Query: 35  EILIKVEAIGVNRPDVMQRKGLYPPPKNANPILGLEVAGKIVDLGENTTHWNIGDEVCAL 94
           E+ ++V+A G+N  DV+   GL P  +     LGLE +G +  +G   T   +GD V  L
Sbjct: 2   EVEVEVKAAGLNFRDVLVALGLLPGDETP---LGLECSGIVTRVGSGVTGLKVGDRVMGL 58

Query: 95  VNGGGYAEYCLSHQGHTLPIPKGYNAIQAASLPESFFTVWANLFQTANLRSGQTVLIHGG 154
             G  +A +        + IP   +  +AA+LP ++ T +  L   A L+ G++VLIH  
Sbjct: 59  APGA-FATHVRVDARLVVKIPDSLSFEEAATLPVAYLTAYYALVDLARLQKGESVLIHAA 117

Query: 155 SSGIGTTAIQLASYFGATVYTTAKSEEKCLACLKLGAKHAINYLKE-------------- 200
           + G+G  AIQLA + GA V+ T  SEEK              +L+E              
Sbjct: 118 AGGVGQAAIQLAQHLGAEVFATVGSEEK------------REFLRELGGPVDHIFSSRDL 165

Query: 201 DFLEILQKETQGRGIDIILDMVGAEYLNQHLTLLSKEGKLIIISFLGGNIATEINLN-PI 259
            F + + + T GRG+D++L+ +  E L      L+  G+ + I     +I +   L    
Sbjct: 166 SFADGILRATGGRGVDVVLNSLSGELLRASWRCLAPFGRFVEIG--KRDILSNSKLGMRP 223

Query: 260 ISKRITITG----STLRRRTDIAKQSIRDSLQLKIWPLLNSHVIAPVIHTVLPLGKVAMA 315
             + ++ +        R R ++ ++ +R+ L+     LL + V+ P+  TV+P      A
Sbjct: 224 FLRNVSFSSVDLDQLARERPELLRELLREVLE-----LLEAGVLKPLPPTVVPSASEIDA 278

Query: 316 HDIMEKSEHIGKIIL 330
             +M+  +HIGK++L
Sbjct: 279 FRLMQSGKHIGKVVL 293