Professors of Biology and Chemistry at MIT have devised a way to entice and visualize a vital enzyme at the moment it turns into active—informing drug development and revealing how organic systems retailer and transfer energy.
The enzyme, ribonucleotide reductase (RNR), is liable for converting RNA building blocks into DNA constructing blocks, in order to develop new DNA strands and repair old ones. RNR is a target for anti-cancer therapies, in addition to the medication that treats viral ailments like HIV/AIDS. However, for decades, scientists struggled to find out how the enzyme is activated because it occurs so quickly.
For the first time, scientists have trapped the enzyme in its active state and noticed how the enzyme changes form, bringing its two subunits closer together and transferring the vitality needed to produce the building blocks for DNA assembly.
Prior to this research, many thought RNR’s two subunits came collectively and fit with perfect symmetry, like a key into a lock. “For 30 years, that is what we thought,” says Catherine Drennan, an MIT Prof. of biology and chemistry and a Howard Hughes Medical Institute investigator.
“However, now, we can see the motion is much more elegant. The enzyme is definitely performing a ‘molecular square dance,’ where completely different parts of the protein hook onto and swing around other elements.”
Former graduate pupil Gyunghoon (Kenny) Kang Ph.D. ’19 is the lead writer. Drennan and JoAnne Stubbe, Prof. emerita of chemistry and biology at MIT, are the senior authors on the research, which appeared in the journal Science on March 26.