CDX1 is a caudal-related homeobox (HOX) transcription factor: that is, it’s a protein which contains a homeodomain, which allows it to modulate gene expression in order to promote correct intestinal cell development, growth and maintenance in both pre- and post-natal humans.
Homeodomain transcription factors are characterised by the presence of both a (1) helix-turn-helix domain, which binds to the major groove of DNA and a (2) flexible, N-terminal arm which is in contact with the minor groove of DNA. These features allow a protein with a homeodomain (i.e. CDX1) to recognise and bind to 5’-TAAT-3’ motifs in the DNA, and thus recruit transcriptional machinery to activate gene expression.
This model showcases the structural features of CDX1 which allow it to bind at a promoter region and act as a transcription factor.
Reference: Silberg, D. G., Swain, G. P., Suh, E. R., & Traber, P. G. (2000). Cdx1 and cdx2 expression during intestinal development. Gastroenterology, 119(4), 961-971.
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