Probing conformational changes in human DNA topoisomerase IIα by pulsed alkylation mass spectrometry.

ABSTRACT: Type II topoisomerases are essential enzymes for solving DNA topological problems by passing one segment of DNA duplex through a transient double-strand break in a second segment. The reaction requires the enzyme to precisely control DNA cleavage and gate opening coupled with ATP hydrolysis. Using pulsed alkylation mass spectrometry, we were able to monitor the solvent accessibilities around 13 cysteines distributed throughout human topoisomerase IIα by measuring the thiol reactivities with monobromobimane. Most of the measured reactivities are in accordance with the predicted ones based on a homology structural model generated from available crystal structures. However, these results reveal new information for both the residues not covered in the structural model and potential differences

SUBMITTER: Chen YT 

PROVIDER: S-EPMC3408185 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature