Chemical transformations on the surface of iron- and sulfur-containing molecules played a key role in the emergence of life on earth. Many biochemical processes that sustain life in today’s biological world continue to depend on such iron-sulfur surfaces, which have been captured within proteins commonly referred to as iron-sulfur proteins. 

Dennis Dean, the Stroobants Professor of Biotechnology and director of the Fralin Life Science Institute, and his research colleagues discovered how iron and sulfur, two otherwise toxic chemicals, can be combined inside cells to form the iron-sulfur clusters necessary to enable nitrogen fixation and other aspects of cellular metabolism. This work has captured the attention of the scientific community because it is now known that defects in the biological formation of iron-sulfur clusters are linked to a variety of debilitating human genetic disorders.

For this and other research contributions, as well as his service to his profession, and leadership in education and outreach to students at all levels, Dean was recently named a University Distinguished Professor by the Virginia Tech Board of Visitors, the pre-eminent faculty rank that is bestowed on no more than one percent of the university's faculty.

For the past three decades, Dean has focused his research on the genetic determinants and chemical mechanism of an iron-sulfur protein called nitrogenase. Nitrogenase is responsible for the “fixation” of nitrogen in the atmosphere to form nitrogenous fertilizers. There is a potential for significant agronomic, economic, and ecological impact of nitrogen fixation research because the existence two-thirds of the world’s population relies on the application of nitrogen fertilizers to maintain crop production. During the course of this work Dean and his collaborators made the discovery about how iron and sulfur form critical iron-sulfur clusters.

As a result of the application of innovative, multidisciplinary approaches, “Dennis has made several discoveries whose fundamental importance and profound impact have rendered them, literally, ‘textbook’ material,” said Peter J. Kennelly, head of the biochemistry department at Virginia Tech. “These include his contribution to the discovery of the role of feedback regulatory circuits in the control of protein translation, while he was a post-doctoral Fellow at the University of Wisconsin, the elucidation of key facets of the complex and highly elusive molecular mechanism of nitrogenase, and the mapping of the complex pathway by which iron-sulfur clusters are assembled and integrated into proteins.”

Dean’s research is recognized worldwide. He has published 160 articles that have been cited in the scientific literature more the 6,000 times. He currently serves on the editorial boards of the Journal of Bacteriology and the Journal of Biological Chemistry and has recently served on the publications board for the American Society for Biochemistry and Molecular Biology. He has received extramural funding to support his research since 1975, including awards from the U.S. Department of Agriculture, National Science Foundation, National Institutes of Health, and Office of Naval Research.

Dean has been involved in both undergraduate and graduate instruction, offering courses in general microbiology, gene regulation, and laboratory applications. He currently serves as academic advisor to 40 undergraduate students. His teaching and service has extended outside the university with participation in the development and oversight of the Fralin outreach program, which serves thousands of high school students each year. He has been actively and continuously engaged in professional service throughout his career, having served on numerous peer-review and site-visit panels and chaired and organized international conferences, including two Gordon Research Conferences.

Dean directed the Fralin Biotechnology Center for seven years and led the transformation of the center into the Fralin Life Science Institute. As director of the institute, Dean continues to provide leadership and resources “to increase the quality, quantity, and competitiveness of life science research, education, and outreach at Virginia Tech.” The institute supports faculty members and students from many departments across campus. Research pursued under the umbrella of the Fralin Life Science Institute includes vector-borne and infectious diseases, obesity, inflammation, cell biology, and molecular plant sciences. He also served as acting director of the Virginia Tech Carilion Research Institute, with primary responsibility for oversight of laboratory design and financial management.

Dean received his bachelor's degree from Wabash College and was a pre-doctoral National Institutes Trainee at Purdue University where he earned a Ph.D. in molecular biology. He was an National Institutes of Health postdoctoral Fellow at the University of Wisconsin and began his independent scientific career at the Kettering laboratory. He joined the faculty at Virginia Tech in 1985, where he is now a professor of biochemistry.

Dedicated to its motto, Ut Prosim (That I May Serve), Virginia Tech takes a hands-on, engaging approach to education, preparing scholars to be leaders in their fields and communities. As the commonwealth’s most comprehensive university and its leading research institution, Virginia Tech offers 240 undergraduate and graduate degree programs to more than 31,000 students and manages a research portfolio of $513 million. The university fulfills its land-grant mission of transforming knowledge to practice through technological leadership and by fueling economic growth and job creation locally, regionally, and across Virginia.


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