Joan B. Broderick
Montana State University
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Primary Section: 21, Biochemistry Secondary Section: 14, Chemistry Membership Type:
Member
(elected 2022)
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Biosketch
Joan Broderick is a bioinorganic chemist known for her work on radical S-adenosylmethionine (SAM) enzymes and the mechanism by which these enzymes initiate radical reactions throughout biology, as well as her contributions to understanding iron-sulfur cluster assembly during hydrogenase maturation. Broderick was born in San Diego, California and lived with her family in multiple states over the following ten years before settling in Bellevue, Washington where she spent the remainder of her childhood and graduated from Forest Ridge School in 1983. She received a B.S. in chemistry from Washington State University in 1987, and a Ph.D. in inorganic chemistry from Northwestern University in 1992, where she worked on nonheme iron dioxygenases with T.V. O'Halloran. She was a postdoctoral fellow studying the B12-dependent ribonucleotide reductase with JoAnne Stubbe at MIT before joining the faculty of Amherst College in 1993, where she began her work on radical SAM enzymes. She moved to Michigan State University in 1998, and to Montana State University in 2005. She is a Fellow of the American Association for the Advancement of Science, and a member of both the National Academy of Sciences and the American Academy of Arts and Sciences.
Research Interests
Joan Broderick's lab is interested in the biological chemistry of iron-sulfur clusters, especially as it relates to catalysis of radical reactions and the mechanisms by which complex iron-sulfur clusters are assembled in biology. They have provided insights into the fundamental chemistry by which radical SAM enzymes use an iron-sulfur cluster and S-adenosylmethionine (SAM) to initiate diverse radical reactions found throughout nature. These radical SAM reactions begin with coordination of SAM to the unique iron of the enzyme-bound iron-sulfur cluster, followed by the reductive cleavage of SAM and subsequent formation of a central organometallic intermediate in which the SAM-derived deoxyadenosyl moiety is directly bound to the iron-sulfur cluster. Homolytic cleavage of the iron-carbon bond yields a deoxyadenosyl radical that initiates radical chemistry on the substrate. Radical SAM enzymes catalyze key reactions in a wide range of biological processes, including cofactor biosynthesis, natural product biosynthesis, tRNA modification, the antiviral response, and the assembly of complex biological metal clusters. Broderick's lab has shown that a radical SAM enzyme synthesizes carbon monoxide and cyanide from tyrosine during hydrogenase maturation, and that a precursor cluster is assembled on a scaffold protein prior to being transferred to the hydrogenase.
