PAXPaired Box domain
|SMART accession number:||SM00351|
|Interpro abstract (IPR001523):|
The paired domain is an approximately 126 amino acid DNA-binding domain, which is found in eukaryotic transcription regulatory proteins involved in embryogenesis. The domain was originally described as the 'paired box' in the Drosophila protein paired (prd) [(PUBMED:2877747), (PUBMED:3123319)]. The paired domain is generally located in the N-terminal part. An octapeptide [(PUBMED:10811620)] and/or a homeodomain can occur C-terminal to the paired domain, as well as a Pro-Ser-Thr-rich C terminus.
Paired domain proteins can function as transcription repressors or activators. The paired domain contains three subdomains, which show functional differences in DNA-binding. The crystal structures of prd and Pax proteins show that the DNA-bound paired domain is bipartite, consisting of an N-terminal subdomain (PAI or NTD) and a C-terminal subdomain (RED or CTD), connected by a linker. PAI and RED each form a three-helical fold, with the most C-terminal helices comprising a helix-turn-helix (HTH) motif that binds the DNA major groove. In addition, the PAI subdomain encompasses an N-terminal beta-turn and beta-hairpin, also named 'wing', participating in DNA-binding. The linker can bind into the DNA minor groove. Different Pax proteins and their alternatively spliced isoforms use different (sub)domains for DNA-binding to mediate the specificity of sequence recognition [(PUBMED:11103953), (PUBMED:15148315)].
Some proteins known to contain a paired domain:
The Pax proteins:
|GO process:||regulation of transcription, DNA-dependent (GO:0006355)|
|GO function:||DNA binding (GO:0003677)|
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- Evolution (species in which this domain is found)
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- Disease (disease genes where sequence variants are found in this domain)
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