May 5
Chemistry Department Seminar: Catherine Drennan
The Jerry and Jean Mohrig Lecture
Shake, Rattle & Roll: Capturing Snapshots of Metalloproteins in Action
Catherine L. Drennan
Howard Hughes Medical Institute and Departments of Chemistry and Biology,
Massachusetts Institute of Technology, Cambridge, MA
Metalloproteins are responsible for remarkable catalytic conversions such as the reduction of ribonucleotides, the splitting of dinitrogen, and the fixation of carbon. Here the conformational gymnastics involved in ribonucleotide reduction by ribonucleotide reductases (RNRs) will be discussed. RNRs are key players in nucleic acid metabolism, converting ribonucleotides to deoxyribonucleotides. As such, they maintain the intracellular balance of deoxyribonucleotides to ensure the fidelity of DNA replication and repair. The best-studied RNR is the Fe-dependent enzyme from E. coli, which employs two protein-subunits to catalyze its reaction. Applications of biophysical methods to the study of RNRs have revealed the importance of subunit oligomeric state to overall enzyme activity, and suggest that dramatic protein conformational changes are in play.