Chromosomol DNA fragments from mouse cells exposed to an intercalating agent contain a 175-kdalton terminal polypeptide.
A 175 kdalton (kDa) polypeptide is bound covalently to the chromosomal DNA fragments from mouse cells exposed to the intercalating agent 4'-[(9-acridinyl)-amino]methansulphon-m-anisidide. Electron microscopy shows a terminal protein on the DNA fragments, whose 5'-termini are blocked. Since the relative molecular mass of topoisomerase II polypeptide chains is also about 175 kDa and topoisomerase II inhibitors prevent intercalator-induced DNA fragmentation, we propose that the polypeptide bound covalently to the 5'-terminus of the DNA fragments is a polypeptide derived from frequently integrated topoisomerase II operating to normalize torsional stress resulting from intercalation.
D000609:Aminoacridines / Q000494:pharmacology*; D000677:Amsacrine; D000818:Animals; D002460:Cell Line; D002875:Chromosomes / Q000378:metabolism*; D004247:DNA / Q000302:isolation & purification; D003852:Deoxyribonucleoproteins / Q000302:isolation & purification / Q000378:metabolism*; D007364:Intercalating Agents / Q000494:pharmacology*; D051379:Mice; D008854:Microscopy, Electron; D008970:Molecular Weight
D000609:Aminoacridines; D003852:Deoxyribonucleoproteins; D007364:Intercalating Agents; D000677:Amsacrine; D004247:DNA