Figure 1

CNBP binding sites and PQSs detected in TCOF1 promoter. (A) Logo (and below the 14-nucleotide consensus sequence) representing CNBP DNA-consensus binding site. CNBP binding sequence was predicted²⁴. Asterisks indicate the six more conserved guanine residues as defined by the authors. (B) PQS consensus and diagram of G4 folding. Guanine-rich sequences capable of forming canonical G-quadruplexes consists in four tracts with 2–5 Guanine (orange), and between them, loops of variable nucleotides with different lengths (black). These kinds of sequences can fold into intramolecular stacked G-tetrads stabilized by coordination with monovalent cations. (C) Scheme of the human TCOF1 EPR (the region between the transcription start site (TSS, indicated with an arrow and + 1) and 5000 bp upstream) detailing the CNBP binding sites (CNBP-BS, green arrowheads) and PQSs (yellow diamonds). The 5′ untranslated region (5′UTR) is indicated by a black box. Below, the table shows the sequences (named according to their distance in bp to the TSS and with the guanine tetrads probably involved G4 formation marked in orange) and coordinates of each PQS that overlapped with CNBP binding sites found in the TCOF1 promoter. Also included are the results (scores) of web-based G4 predicting algorithms, QGRS-Mapper and G4Hunter.