Molecular characterization of two types of 22 kilodalton alpha-zein genes in a gene cluster in maize.
Five genes of the alpha-zein subfamily four (SF4) are located in a 56 kb genomic region of the maize inbred line W22. Their nucleotide and deduced amino acid sequences have been determined. The sequences define two types of alpha-zein SF4 genes-type 1 (T1) and type 2 (T2). The single T1 alpha-zein SF4 gene codes for an alpha-zein protein with a M(r) of about 22,000. This is the first alpha-zein SF4 gene sequenced that contains no early in-frame stop codons in its coding sequence. The four T2 alpha-zein SF4 genes in this cluster contain one or two early in-frame stop codons. In addition, our T1 and T2 genes differ markedly in the base sequences of their distal 5' non-translated flanking regions. The nucleotide and the deduced amino acid sequences of these two types of alpha-zein SF4 genes are similar (greater than 90%) to one another and to all known alpha-zein SF4 genes and cDNAs. Of the known W22 alpha-zein SF4 genes, only one in six does not contain an early in-frame stop codon. If the number of alpha-zein SF4 genes is 15-20, then we estimate that only about 4 of the W22 alpha-zein SF4 genes are without in-frame early stop codons.
Liu
C N
CN
Department of Plant Biology, University of Minnesota, St. Paul 55108.
Rubenstein
I
I
D000595:Amino Acid Sequence; D001483:Base Sequence; D003062:Codon / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D015183:Restriction Mapping; D003313:Zea mays / Q000235:genetics*; D015028:Zein / Q000235:genetics*
D003062:Codon; D015028:Zein