CAAT box

In molecular biology, a CAAT box is a distinct pattern of nucleotides that occur upstream by 75-80 bases to the initial transcription site. The CAAT box signals the binding site for the RNA transcription factor, and is typically accompanied by a conserved consensus sequence. It is an invariant DNA sequence at about minus 70 base pairs from the origin of transcription in many eukaryotic promoters. Genes that have this element seem to require it for the gene to be transcribed in sufficient quantities. It is frequently absent from genes that encode proteins used in virtually all cells.

A CAAT box is a feature frequently found before eukaryote coding regions, but is not found in prokaryotes.