A novel class of plant proteins containing a homeodomain with a closely linked leucine zipper motif.
The homeobox, a 183 bp DNA sequence element, was originally identified as a region of sequence similarity between many Drosophila homeotic genes. The homeobox codes for a DNA-binding motif known as the homeodomain. Homeobox genes have been found in many animal species, including sea urchins, nematodes, frogs, mice and humans. To isolate homeobox-containing sequences from the plant Arabidopsis thaliana, a cDNA library was screened with a highly degenerate oligonucleotide corresponding to a conserved eight amino acid sequence from the helix-3 region of the homeodomain. Using this strategy two cDNA clones sharing homeobox-related sequences were identified. Interestingly, both of the cDNAs also contain a second element that potentially codes for a leucine zipper motif which is located immediately 3' to the homeobox. The close proximity of these two domains suggests that the homeodomain-leucine zipper motif could, via dimerization of the leucine zippers, recognize dyad-symmetrical DNA sequences.
Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, Italy.
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Sessa
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Morelli
D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins; D001483:Base Sequence; D004247:DNA / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification; D005801:Genes, Homeobox; D018398:Homeodomain Proteins; D016350:Leucine Zippers / Q000235:genetics*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification; D011487:Protein Conformation
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C069386:HB-2 protein, Arabidopsis; D018398:Homeodomain Proteins; D010940:Plant Proteins; D004247:DNA