DNA, RNA, and Associated Enzymes

Intercalating compounds also directly inhibit DNA replication and transcription. RNA is basically single stranded, but most RNA molecules have double-stranded stem structures because of complementary base pairing. These double-stranded regions can also be intercalated. Therefore, many intercalating SM are also inhibitors of DNA and RNA polymerases, of reverse transcriptase, and even of DNA topoisomerases and possibly telomerase. 

DNA topoisomerase I and II play important roles in DNA replication and transcription. Their inhibition usually leads to cell-cycle arrest and cell death by apoptosis. During replication, DNA needs to be uncoiled. In order to avoid torsions and rotations, DNA is cleaved by DNA topoisomerase 1, which forms 

10-Hydro xy-camptothecin Camptotheca acuminata Topoisomerase I inhibitor cell-cycle (78,79) 

Ocotea leucoxylon (Lauraceae) Ecteinascidia turbinate (tunicate) 

DNA intercalation binding to single stranded poly (rA) inhibitor of topoisomerase I and II inhibition of DNA potymerase, reverse transcriptase 

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The biogenesis of these organelles involves a special set of problems that arise in part from their complex gross morphology and the possession of an independent store of informational molecules (DNA,RNA) and associated enzymes for transcription and translation of the genetic information. Chapter 2 deals with the extent to which the autonomy of mitochondria is determined by its own genetic system Chapter 7 deals with the comparable problem in chloroplasts. 

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