InterPro domain: IPR009057

General Information

  • Identifier IPR009057
  • Description Homeobox-like domain superfamily
  • Number of genes 44243
  • Gene duplication stats Loading...

Abstract

Homeobox domain (also known as homeodomain) proteins are transcription factors that share a related DNA binding homeodomain [ 1 ]. The homeodomain was first identified in a number of Drosophila homeotic and segmentation proteins, but is now known to be well conserved in many other animals, including vertebrates. The domain binds DNA through a helix-turn-helix (HTH) structure. The HTH motif is characterised by two alpha-helices, which make intimate contacts with the DNA and are joined by a short turn. The second helix binds to DNA via a number of hydrogen bonds and hydrophobic interactions, which occur between specific side chains and the exposed bases and thymine methyl groups within the major groove of the DNA. The first helix helps to stabilise the structure. Many proteins contain homeodomains, including Drosophila Engrailed, yeast mating type proteins, hepatocyte nuclear factor 1a and HOX proteins.

The homeodomain motif is very similar in sequence and structure to domains in a wide range of DNA-binding proteins, including recombinases, Myb proteins, GARP response regulators, human telomeric proteins (hTRF1), paired domain proteins (PAX), yeast RAP1, centromere-binding proteins CENP-B and ABP-1, transcriptional regulators (TyrR), AraC-type transcriptional activators, and tetracycline repressor-like proteins (TetR, QacR, YcdC) [ 2 , 3 , 4 ].


1. Target genes of homeodomain proteins. Bioessays 21, 267-70
2. Molecular structure of the GARP family of plant Myb-related DNA binding motifs of the Arabidopsis response regulators. Plant Cell 14, 2015-29
3. Solution structure of the DNA-binding domain of human telomeric protein, hTRF1. Structure 6, 1057-65
4. The complex formed between Tet repressor and tetracycline-Mg2+ reveals mechanism of antibiotic resistance. J. Mol. Biol. 247, 260-80

Species distribution

Gene table

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