title: Molecular evolution of the homeodomain family of transcription factors.
abstract: The homeodomain family of transcription factors plays a fundamental role in a diverse set of functions that include body plan specification, pattern formation and cell fate determination during metazoan development. Members of this family are characterized by a helix-turn-helix DNA-binding motif known as the homeodomain. Homeodomain proteins regulate various cellular processes by specifically binding to the transcriptional control region of a target gene. These proteins have been conserved across a diverse range of species, from yeast to human. A number of inherited human disorders are caused by mutations in homeodomain-containing proteins. In this study, we present an evolutionary classification of 129 human homeodomain proteins. Phylogenetic analysis of these proteins, whose sequences were aligned based on the three-dimensional structure of the homeodomain, was performed using a distance matrix approach. The homeodomain proteins segregate into six distinct classes, and this classification is consistent with the known functional and structural characteristics of these proteins. An ancestral sequence signature that accurately describes the unique sequence characteristics of each of these classes has been derived. The phylogenetic analysis, coupled with the chromosomal localization of these genes, provides powerful clues as to how each of these classes arose from the ancestral homeodomain.
authors.affiliation: Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4470, USA.
authors.forename: S
authors.initials: S
authors.lastname: Banerjee-Basu
authors.forename: A D
authors.initials: AD
authors.lastname: Baxevanis
mesh_terms: D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D002877:Chromosomes, Human / Q000235:genetics; D019295:Computational Biology; D017124:Conserved Sequence; D019143:Evolution, Molecular; D030342:Genetic Diseases, Inborn / Q000235:genetics; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000145:classification* / Q000235:genetics; D006801:Humans; D020407:Internet; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry* / Q000145:classification* / Q000235:genetics
chemical_list: D018398:Homeodomain Proteins; D014157:Transcription Factors