CAAT box

The left model is of the complex of NF-YC/NF-YB with the CCAAT element from the pro- 2(I) collagen promoter. The DNA backbone is shown as ribbons (purple) with the bases displayed. The two possible locations of the CCAAT box, according to the modeling, have been colored cyan. For the right model of the NF-Y/CCAAT complex. NF-YC, NF-YB and DNA are colored as in figure on the left, whereas NF-YA is colored blue. The two alternative positions for the linker connecting NF-YA1 and NF-YA2 sub-domains are shown as blue dotted lines. Secondary structure elements of the histone pair that are implicated in NF-YA1 and NF-YA2 recognition (see text) are labeled and colored in red and gray, respectively. For clarity, only the bases for the CCAAT pentanucleotide are shown and labeled.[1]

In molecular biology, a CCAAT box (also sometimes abbreviated a CAAT box or CAT box) is a distinct pattern of nucleotides with GGCCAATCT consensus sequence that occur upstream by 60–100 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. This box along with the GC box is known for binding general transcription factors. Both of these consensus sequences belong to the regulatory promoter. Full gene expression occurs when transcription activator proteins bind to each module within the regulatory promoter. Protein specific binding is required for the CCAAT box activation. These proteins are known as CCAAT box binding proteins/CCAAT box binding factors.

A CCAAT box is a feature frequently found before eukaryote coding regions, but is not found in prokaryotes.[2]

  1. ^ Romier, Christophe; Cocchiarella, Fabienne; Mantovani, Roberto; Moras, Dino (24 October 2002). "The NF-YB/NF-YC Structure Gives Insight into DNA Binding and Transcription Regulation by CCAAT Factor NF-Y". The Journal of Biological Chemistry. 278 (2): 1336–1345. doi:10.1074/jbc.M209635200. PMID 12401788.
  2. ^ Stedman, Thomas Lathrop (6 December 2005). Stedman's Medical Dictionary, Volume 1 (28th ed.). Lippincott Williams & Wilkins. ISBN 9780781733908.