Molecular cloning and characterization of a cDNA for the beta subunit of human alcohol dehydrogenase.

Human alcohol dehydrogenase (ADH) is encoded by at least five genes that fall into three classes. The class I ADH genes encode the three closely related alpha, beta, and gamma polypeptides. Molecular genetic analysis of class I ADH genes has been initiated by isolating a cDNA clone from a human adult liver cDNA library. A synthetic oligonucleotide mixture encoding a portion of the beta subunit of ADH was used as an in situ hybridization probe for the cDNA library. One positively hybridizing clone, pADH12, which contained an 1100-base-pair cDNA insert, was subjected to DNA sequence analysis. The sequence indicated that the cDNA encoded information for the carboxyl-terminal 91 amino acids of a class I ADH and a 3' untranslated region of 593 nucleotides. Comparisons with the carboxyl terminus of the human ADH beta subunit indicated that the cDNA encoded the beta polypeptide. This probe may facilitate genetic studies of various human alcohol-related syndromes, as well as enable basic molecular studies on human ADH gene expression.