Identification of DNA fragments specific to regulatory regions of glucocorticoid-regulated genes by the computer analysis method

The contextual computer analysis was used to study the nucleotide sequences of 33 eucaryotic genes, out of which 12 were regulated by glucocorticoids and 21 were not. This analysis has revealed that the consensus TGTTCT found previously in the 5-flanking regions of genes which are protected by glucocorticoid-receptor complexes from nucleases is unspecific to glucocorticoid-regulated genes. However, the analysis of the sequences flanking the TGTTCT consensus has revealed that the presence of four regularly distributed cytosine residues, one in the consensus itself and three in its vicinity, occurs only in the genes which are regulated by glucocorticoids. Three of the cytosine residues are separated by 8-10 bp while one outer residue is 6 bp away from the nearest cytosine. Distances from the 8 to 10 bp between the cytosine residues in the TGTTCT itself and those in its surroundings mean that they are located in a close proximity at one side of the DNA double helix. It is supposed that in the DNA helix the consensus and the flanking cytosine residues form a specific site for interaction with the glucocorticoid-receptor complex.