Topoisomerase and DNA (VIDEO) University of California - Berkeley This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption A UC Berkeley group has worked out the mechanics of how the enzyme Type II topoisomerase binds a broken DNA strand and stitches it back together before releasing it. Colored portions highlight different structural elements of the enzyme needed for DNA cleavage and movement. Credit James Berger lab/UC Berkeley Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.