>gnl|CDD|176220 cd08259, Zn_ADH5, Alcohol dehydrogenases of the MDR family. NAD(P)(H)-dependent oxidoreductases are the major enzymes in the interconversion of alcohols and aldehydes, or ketones. This group contains proteins that share the characteristic catalytic and structural zinc-binding sites of the zinc-dependent alcohol dehydrogenase family. 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 have 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. A GxGxxG motif after the first mononucleotide contact half allows the close contact of the coenzyme with the ADH backbone. 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 (His-51), the ribose of NAD, a serine (Ser-48), 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 = 332

 Score =  151 bits (384), Expect = 2e-37
 Identities = 92/339 (27%), Positives = 151/339 (44%), Gaps = 53/339 (15%)

Query: 23  LAESPIPQPQKEEILIKVEAIGVNRPDVMQRKGLYPPPKNANP--ILGLEVAGKIVDLGE 80
           + E P P+P   E+LIKV+A GV   D++  KG +P         ILG E+ G + ++GE
Sbjct: 15  IEEVPDPEPGPGEVLIKVKAAGVCYRDLLFWKGFFP---RGKYPLILGHEIVGTVEEVGE 71

Query: 81  NTTHWNIGDEVCAL---------------------------VNGGGYAEYCLSHQGHTLP 113
               +  GD V                                 GG+AEY    +   + 
Sbjct: 72  GVERFKPGDRVILYYYIPCGKCEYCLSGEENLCRNRAEYGEEVDGGFAEYVKVPERSLVK 131

Query: 114 IPKGYNAIQAASLPESFFTVWANLFQTANLRSGQTVLIHGGSSGIGTTAIQLASYFGATV 173
           +P   +   AA       T    L + A ++ G TVL+ G   G+G  AIQLA   GA V
Sbjct: 132 LPDNVSDESAALAACVVGTAVHALKR-AGVKKGDTVLVTGAGGGVGIHAIQLAKALGARV 190

Query: 174 YTTAKSEEKCLACLKLGAKHAINYLK--EDFLEILQKETQGRGIDIILDMVGAEYLNQHL 231
               +S EK     +LGA + I+  K  ED  ++        G D+++++VG+  + + L
Sbjct: 191 IAVTRSPEKLKILKELGADYVIDGSKFSEDVKKLG-------GADVVIELVGSPTIEESL 243

Query: 232 TLLSKEGKLIIISFLGGNIATEINLNPIISKRITITGSTLRRRTDIAKQSIRDSLQLKIW 291
             L+K G+L++I  +  + A  +    +I K I I GS    + D     + ++L+    
Sbjct: 244 RSLNKGGRLVLIGNVTPDPA-PLRPGLLILKEIRIIGSISATKAD-----VEEALK---- 293

Query: 292 PLLNSHVIAPVIHTVLPLGKVAMAHDIMEKSEHIGKIIL 330
            L+    I PVI  V+ L  +  A + ++  + +G+I+L
Sbjct: 294 -LVKEGKIKPVIDRVVSLEDINEALEDLKSGKVVGRIVL 331