DNA topoisomerase I together with the other cellular DNA topoisomerases releases the torsional stress from DNA caused by processes such as replication, transcription and recombination. Despite the well-defined knowledge of its mechanism of action, DNA topoisomerase I in vivo activity has been only partially characterized. In fact the basic question concerning the capability of the enzyme to cleave and rejoin DNA wrapped around a histone octamer remains still unanswered. By studying both in vivo and in vitro the cleavage activity of DNA topoisomerase I in the presence of camptothecin on a repeated trinucleotide sequence, (TTA)35, lying in chromosome XIII of Saccharomyces cerevisiae, we can conclude that nucleosomes represent a physical barrier for the enzyme activity. © The Authors.
Nucleosomes represent a physical barrier for cleavage activity of DNA topoisomerase I in vivo / DI FELICE, Francesca; Chiani, Francesco; Camilloni, Giorgio. - In: BIOCHEMICAL JOURNAL. - ISSN 0264-6021. - STAMPA. - 409:3(2008), pp. 651-656. [10.1042/bj20070893]
Nucleosomes represent a physical barrier for cleavage activity of DNA topoisomerase I in vivo
DI FELICE, Francesca;CHIANI, Francesco;CAMILLONI, Giorgio
2008
Abstract
DNA topoisomerase I together with the other cellular DNA topoisomerases releases the torsional stress from DNA caused by processes such as replication, transcription and recombination. Despite the well-defined knowledge of its mechanism of action, DNA topoisomerase I in vivo activity has been only partially characterized. In fact the basic question concerning the capability of the enzyme to cleave and rejoin DNA wrapped around a histone octamer remains still unanswered. By studying both in vivo and in vitro the cleavage activity of DNA topoisomerase I in the presence of camptothecin on a repeated trinucleotide sequence, (TTA)35, lying in chromosome XIII of Saccharomyces cerevisiae, we can conclude that nucleosomes represent a physical barrier for the enzyme activity. © The Authors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.