NUCLEOTIDE-SEQUENCE OF A GENE FROM ARABIDOPSIS-THALIANA ENCODING A MYB HOMOLOG

A gene encoding a proto-oncogene, a myb-related gene named Atmybl, was cloned from Arabidopsis thaliana, and its nucleotide sequence was determined. The Atmybl gene contains an intron of 494 bp, and there are no highly homologous sequences present in the A. thaliana genome, but evidence was found that other myb-related genes exist. In the 5' flanking region, we found several typical cis-acting elements found in plant promoters. Sequence comparisons revealed that the ATMYB1 protein has a putative DNA-binding domain with two repeats of tryptophan clusters, which is common in MYB-related proteins in plants, while animal MYB-related proteins contain DNA-binding domains with three repeats of tryptophan clusters. The putative DNA-binding domain of the ATMYB1 protein has higher homology with that of the human c-MYB protein than with those of other plant MYB proteins.