Sequence analysis of linked maize 22 kDa α-zein genes

We have determined the nucleotide sequence of a 7343 bp zein genomic clone (gZ22.8H3) from the maize inbred W64A. Computer-aided analysis of the DNA sequence revealed two contiguous 22 kDa α-zein genes. The 5′ gene (gZ22.8) encodes a complete polypeptide and contains putative regulatory sequences in both the 5′ and 3′ flanking regions that are typical of zein genes. In contrast, the 3′ gene (ψgZ22.8) appears to be a pseudogene, because it contains numerous insertions and deletions that would prevent translation of the mRNA. Alignment of the 5′ and 3′ flanking sequences of both genes indicated that they resulted from a 3.3 kb DNA duplication event.