A universal target sequence is bound in vitro by diverse homeodomains.
To determine the number of DNA binding proteins capable of binding a consensus Engrailed binding site, this consensus sequence was used to screen a library of Drosophila cDNA clones in a bacteriophage expression vector. We retrieved clones encoding 20 distinct DNA binding domains, 17 of which are homeodomains. Binding to a variety of oligonucleotides confirms the related sequence specificity of the retrieved binding domains. Nonetheless, the homeodomains have remarkably diverse amino acid sequences. We conclude that during the evolutionary divergence of homeodomains, the specificity of DNA binding has been much more highly conserved than the amino acid sequence.
Kalionis
B
B
Department of Biochemistry and Biophysics, University of California at San Francisco 94143-0448.
O'Farrell
P H
PH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004274:DNA, Recombinant / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D005796:Genes; D005801:Genes, Homeobox; D017344:Genes, Insect; D018398:Homeodomain Proteins; D007301:Insect Hormones / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013379:Substrate Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D018076:DNA, Complementary; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C063459:En protein, Drosophila; D018398:Homeodomain Proteins; D007301:Insect Hormones; D014157:Transcription Factors