Molecular analysis of the ADH1-Cm allele of maize

The Adh1-Cm allele and each gene in the Adh1-FCm duplication have been cloned and restriction-mapped. Of the Cm allele 6 kb was sequenced. A single amino acid substitution of aspartate for tyrosine at residue 52 accounts for the altered enzymatic properties of the Cm protein. Comparison of the nucleotide sequence to that of Adh1-1F and Adh1-1S shows structural and restriction site polymorphisms in the 3' flanking DNA. Cm lacks the insertion sequence present in 1F and 1S and contains a complex sequence composed of two direct repeats and an inverted repeat. The two genes of the duplication allele have similar restriction maps to Cm and each other.