Identification of Conservative Patterns of G-quadruplexes and Transcription Factor Binding Sites

Next-generation sequencing experiments have confirmed genome-wide G-quadruplex formation. It is known that such structures are located in promoter regions of genes and participate in regulation of transcription. This work is devoted to the study of association between conservative G-quadruplexes in promoters of human, mouse and drosophila orthologs and transcription factor binding sites, in particular, ZF-TF binding sites. It was shown that orthologs of three species, containing conservative G-quadruplexes, can be divided into several groups based on molecular functions. Orthologs which constitute the largest group are involved in such functions as DNA binding and transcription regulator activity. About a quarter of proteins encoded by these orthologs are transcription factors, half of which belong to zinc finger proteins group. The study of transcription factor binding sites in promoters of these orthologs showed that site can intersect G-quadruplex or be located in the region of G-quadruplex. Among the transcription factors associated with these motifs, zinc finger transcription factors stand out. We hypothesized about self-regulation of transcription factors and DNA-binding proteins by means of G-quadruplexes associated with their binding sites in human, mouse and drosophila orthologs. The results obtained suggest that this mechanism evolved evolutionarily for zinc finger proteins.