Single-molecule Studies of DNA Topology by Type IA Topoisomerase I and III.

Ksenia A. Terekhova
Stanford Medicine
Structural Biology
900 Quarry Road Extension
Stanford, CA 94305

Topoisomerase I and III are enzymes capable of changing DNA topology by resolving negative supercoils and catenate/decatenate DNA molecules with single-stranded DNA regions. To elucidate the mechanistic differences between these two, related topoisomerases, we conducted single-molecule relaxation and decatenation studies on various types of DNA substrates. The determined kinetic characteristics of topoisomerase I and III point out the origin of their distinct behavior.