>gnl|CDD|176202 cd08240, 6_hydroxyhexanoate_dh_like, 6-hydroxyhexanoate dehydrogenase. 6-hydroxyhexanoate dehydrogenase, an enzyme of the zinc-dependent alcohol dehydrogenase-like family of medium chain dehydrogenases/reductases catalyzes the conversion of 6-hydroxyhexanoate and NAD(+) to 6-oxohexanoate + NADH and H+. 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. 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, 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 = 350

 Score = 86.9 bits (216), Expect = 8e-18
 Identities = 75/310 (24%), Positives = 120/310 (38%), Gaps = 60/310 (19%)

Query: 7   MRHVAMSGYGKSNVMFLAESPIPQPQKEEILIKVEAIGVNRPDVMQRKGLY--------- 57
           M+  A+   GK   +   E   P+P   E+L+KV A GV   D+    G Y         
Sbjct: 1   MKAAAVVEPGKP--LEEVEIDTPKPPGTEVLVKVTACGVCHSDLHIWDGGYDLGGGKTMS 58

Query: 58  ------PPPKNANPILGLEVAGKIVDLGENTTHWNIGDEV-------------------- 91
                   P     +LG E+ G++V +G +     +GD+V                    
Sbjct: 59  LDDRGVKLPL----VLGHEIVGEVVAVGPDAADVKVGDKVLVYPWIGCGECPVCLAGDEN 114

Query: 92  -CA------LVNGGGYAEYCL-SHQGHTLPIPKGYNAIQAASLPESFFTVWANLFQTANL 143
            CA      +   GGYAEY +  H  + +    G +   AA+L  S  T ++ + +    
Sbjct: 115 LCAKGRALGIFQDGGYAEYVIVPHSRYLVDPG-GLDPALAATLACSGLTAYSAV-KKLMP 172

Query: 144 RSGQT--VLIHGGSSGIGTTAIQLASYFGATVYTTA-KSEEKCLACLKLGAKHAINYLKE 200
                  V+I  G+ G+G  A+ L    G          E K  A    GA   +N    
Sbjct: 173 LVADEPVVII--GAGGLGLMALALLKALGPANIIVVDIDEAKLEAAKAAGADVVVNGSDP 230

Query: 201 DFLEILQKETQGRGIDIILDMVGAE-YLNQHLTLLSKEGKLIIISFLGGNIATEINLNPI 259
           D  + + K   G G+D ++D V      +    +L+K GKL+++   GG     + L  +
Sbjct: 231 DAAKRIIKAAGG-GVDAVIDFVNNSATASLAFDILAKGGKLVLVGLFGGEA--TLPLPLL 287

Query: 260 ISKRITITGS 269
             + +TI GS
Sbjct: 288 PLRALTIQGS 297