G-quadruplexes (G4), non-canonical secondary DNA structures, are intensively investigated for a long time. In eukaryotic organisms they play an important role in the regulation of gene expression and DNA repair. G4 have also been found in the genomes of numerous bacteria and archaea, but their functional role has not yet been fully explored. Nevertheless, their participation in the formation of antigenic variability, pathogenicity, antibiotic resistance and survival in extreme conditions has been established. Currently, many tools have been developed to detect potential G4 sequences and confirm their formation ability. Since the controlled formation and resolution of the quadruplex are significant means for the regulation of genes critical for survival, a promising direction is the search for ligands - compounds that can have a stabilizing effect on the quadruplex structure and thereby alter gene expression. Currently, a number of ligands are already known, their use stops the growth of pathogenic microorganisms. G4 ligands are of interest as potential antibiotics, which are extremely relevant due to the wide spread of drug resistant pathogens.
G-kvadrupleksy (G4), predstavliaiushchie soboĭ nekanonicheskie vtorichnye struktury DNK, intensivno issleduiutsia na protiazhenii dlitel'nogo vremeni. U éukariot oni igraiut vazhnuiu rol' v reguliatsii ékspressii genov i reparatsii DNK. G4 takzhe byli obnaruzheny v genomakh mnogochislennykh bakteriĭ i arkheĭ, odnako ikh funktsional'naia rol' okonchatel'no ne vyiasnena. Izvestno, chto G4 uchuvstvuiut v formirovanii antigennoĭ izmenchivosti, patogennosti, antibiotikoustoĭchivosti i vyzhivanii v ékstremal'nykh usloviiakh. Razrabotano dostatochno mnogo instrumentov po obnaruzheniiu potentsial'nykh G4 posledovatel'nosteĭ i podtverzhdeniiu ikh formirovaniia. Poskol'ku kontroliruemoe obrazovanie i razreshenie kvadrupleksa predstavliaet soboĭ vazhnyĭ instrument reguliatsii kriticheski znachimykh dlia vyzhivaniia genov, perspektivnym napravleniem issledovaniĭ iavliaetsia poisk ligandov — soedineniĭ, sposobnykh okazyvat' na strukturu kvadrupleksa stabiliziruiushchee deĭstvie i tem samym ostanavlivat' ékspressiiu genov. V nastoiashchee vremia uzhe izvesten riad ligandov, primenenie kotorykh ostanavlivaet rost patogennykh mikroorganizmov. G4-ligandy predstavliaiut interes v kachestve potentsial'nykh protivomikrobnykh preparatov, chto iavliaetsia chrezvychaĭno aktual'nym v sviazi s shirokim rasprostraneniem patogennykh mikroorganizmov s lekarstvennoĭ ustoĭchivost'iu.
Keywords: DNA secondary structure; antigenic variability; ligands; quadruplexes; transcription regulation.