Watch: When strands of genetic material called DNA get twisted too tightly, machines called ‘topoisomerases’ come to the rescue. The topoisomerase shown in this video prevents breaks in genes within DNA that is wound too tight. If the function of this enzyme is interrupted, cells die because they can’t keep genes intact. To kill cancer cells, scientists have developed drugs to disrupt this enzyme’s gene-protecting effects. But some of these drugs can have unwanted side effects. To help solve this problem, Johns Hopkins biophysicist James Berger and his team are looking at the molecular blueprint of enzymes to get a better idea of how drugs and enzymes interact. Their research may help scientists develop improved classes of drugs that are more efficient at killing bacterial or cancer cells and with fewer side effects.

Caption written by Vandana Suresh, Science Writing Intern for the Johns Hopkins Institute for Basic Biomedical Sciences.