This is the catalytic domain of alcohol dehydrogenases. Many of them contain an inserted zinc binding domain. This domain has a GroES-like structure [1-2].
Alcohol dehydrogenase is the enzyme responsible for the conversion of alcohol to acetaldehyde that occurs in the cytoplasm, one of the three routes whereby acetaldehyde can be formed from alcohol before it passes into the mitochondria for the completion of the breakdown process. As a result the enzyme plays a vital role in alcohol metabolism, and inability to process alcohol is most commonly caused by deficiency.
This alcohol dehydrogenase is zinc-dependent and belongs to the class I zinc-containing ADH superfamily. Whilst this enzyme binds two zinc ions, only one of these is actively involved in catalysis. It has been noted that that many ADHs that lack a His at position 51 often have an analogous histidine at position 47 which can perform the same function (PMID:10970744), i.e. activating the Ser/Thr 48 for its catalytic function, also that the residue at position 48 is interchangeable between serine and threonine (acts as a general base to deprotonate the OH group of the alcohol substrate).
Defined by 5 residues: CYS:A-46SER:A-48HIS:A-51HIS:A-67CYS:A-174