Homeobox

Homeodomain
The Antennapedia homeodomain protein from Drosophila melanogaster bound to a fragment of DNA.[1] The recognition helix and unstructured N-terminus are bound in the major and minor grooves respectively.
Identifiers
SymbolHomeodomain
PfamPF00046
Pfam clanCL0123
InterProIPR001356
SMARTSM00389
PROSITEPDOC00027
SCOP21ahd / SCOPe / SUPFAM
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary
PDB1ahd​, 1akh​, 1apl​, 1au7​, 1b72​, 1b8i​, 1bw5​, 1cqt​, 1du0​, 1du6​, 1e3o​, 1enh​, 1f43​, 1fjl​, 1ftt​, 1ftz​, 1gt0​, 1hdd​, 1hdp​, 1hf0​, 1hom​, 1ic8​, 1ig7​, 1jgg​, 1k61​, 1kz2​, 1le8​, 1lfb​, 1lfu​, 1mh3​, 1mh4​, 1mnm​, 1nk2​, 1nk3​, 1o4x​, 1ocp​, 1oct​, 1p7i​, 1p7j​, 1pog​, 1puf​, 1qry​, 1s7e​, 1san​, 1uhs​, 1vnd​, 1wi3​, 1x2m​, 1x2n​, 1yrn​, 1yz8​, 1zq3​, 1ztr​, 2cqx​, 2cra​, 2cue​, 2cuf​, 2dmq​, 2e1o​, 2ecb​, 2ecc​, 2h8r​, 2hdd​, 2hi3​, 2hoa​, 2jwt​, 2lfb​, 2p81​, 2r5y​, 2r5z​, 3hdd​, 9ant​

A homeobox is a DNA sequence, around 180 base pairs long, that regulates large-scale anatomical features in the early stages of embryonic development. Mutations in a homeobox may change large-scale anatomical features of the full-grown organism.

Homeoboxes are found within genes that are involved in the regulation of patterns of anatomical development (morphogenesis) in animals, fungi, plants, and numerous single cell eukaryotes.[2] Homeobox genes encode homeodomain protein products that are transcription factors sharing a characteristic protein fold structure that binds DNA to regulate expression of target genes.[3][4][2] Homeodomain proteins regulate gene expression and cell differentiation during early embryonic development, thus mutations in homeobox genes can cause developmental disorders.[5]

Homeosis is a term coined by William Bateson to describe the outright replacement of a discrete body part with another body part, e.g. antennapedia—replacement of the antenna on the head of a fruit fly with legs.[6] The "homeo-" prefix in the words "homeobox" and "homeodomain" stems from this mutational phenotype, which is observed when some of these genes are mutated in animals. The homeobox domain 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.[3][7][8]

  1. ^ PDB: 1AHD​; Billeter M, Qian YQ, Otting G, Müller M, Gehring W, Wüthrich K (December 1993). "Determination of the nuclear magnetic resonance solution structure of an Antennapedia homeodomain-DNA complex". Journal of Molecular Biology. 234 (4): 1084–93. doi:10.1006/jmbi.1993.1661. PMID 7903398.
  2. ^ a b Bürglin TR, Affolter M (June 2016). "Homeodomain proteins: an update". Chromosoma. 125 (3): 497–521. doi:10.1007/s00412-015-0543-8. PMC 4901127. PMID 26464018.
  3. ^ a b Gehring WJ (August 1992). "The homeobox in perspective". Trends in Biochemical Sciences. 17 (8): 277–80. doi:10.1016/0968-0004(92)90434-B. PMID 1357790.
  4. ^ Gehring WJ (December 1993). "Exploring the homeobox". Gene. 135 (1–2): 215–21. doi:10.1016/0378-1119(93)90068-E. PMID 7903947.
  5. ^ "Homeoboxes". Genetics Home Reference. U.S. National Library of Medicine. Archived from the original on 2019-12-21. Retrieved 2019-11-20.
  6. ^ Materials for the study of variation, treated with especial regard to discontinuity in the origin of species William Bateson 1861–1926. London : Macmillan 1894 xv, 598 p
  7. ^ Schofield PN (1987). "Patterns, puzzles and paradigms - The riddle of the homeobox". Trends Neurosci. 10: 3–6. doi:10.1016/0166-2236(87)90113-5. S2CID 53188259.
  8. ^ Scott MP, Tamkun JW, Hartzell GW (July 1989). "The structure and function of the homeodomain". Biochimica et Biophysica Acta (BBA) - Reviews on Cancer. 989 (1): 25–48. doi:10.1016/0304-419x(89)90033-4. PMID 2568852.