top1-mediated DNA cleavage gen.

[svetliachok8888]

Пожалуйста. помогите перевести - top1-mediated DNA cleavage .
Как я понимаю, это расщепление ДНК, опосредованное этим top1. что такое top1?

вот контекст:
It was found that top1-mediated DNA
cleavage was enhanced when the drug was incorporated immediately 3' from a top1
cleavage site on the non scissile strand. This position-specific enhancement was attributable
to an increased DNA cleavage by top1 and was likely to have resulted from a combination

[Dimpassy]

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