Many organisms synthesize compounds that convert topoisomerases into DNA-damaging agents, thereby exploiting the toxic effects inherent in a reaction that requires breaking and resealing DNA. Currently, topoisomerase I and topoisomerase IIα and IIβ are known to be the targets of naturally occurring plant alkaloids and yeast fermentation products. Similar targeting of topoisomerase III is likely but not yet proven. Topoisomerase poisons are believed to bind to DNA, the topoisomerase, or either molecule at or near the region of the enzyme involved in the formation of the DNA-protein covalent linkage. Many topoisomerase poisons, such as the anthracyclines and actinomycin D, are relatively planar hydrophobic compounds that bind to DNA with high affinity by intercalation, which involves stacking of the compound between adjacent base pairs. Here you can see the crystal structure of the topoisomerase II poison 9-amino-[N-(2-dimethylamino)ethyl]acridine-4-carboxamide bound to the DNA hexanucleotide d(CGTACG)2 (PDB code: 465D)
#molecularart ... #immolecular ... #telomere ... #telomerase ... #complex ... #poison ... #chromosome ... #aging ... #cancer ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #telomere ... #telomerase ... #complex ... #poison ... #chromosome ... #aging ... #cancer ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
