John E. Cronan is the Microbiology Alumni Professor at the University of Illinois at Urbana-Champaign and also Professor of Biochemistry. Cronan is a bacterial geneticist/biochemist who has made fundamental contributions in several different fields. He is best known for his work on the synthesis of fatty acids and the related vitamin cofactors, biotin and lipoic acid. By use of Escherichia coli and Bacillus subtilis as model systems his lab was the first to determine the pathways for synthesis of lipoic acid, a key cofactor required throughout biology for aerobic metabolism and amino acid degradation. His lab also determined the first pathways for synthesis of pimelic acid, the source of most of the carbon atoms of the key cofactor of central metabolism, biotin. He also described the first transcriptional regulator of fatty acid metabolism and developed proximity dependent protein biotinylation. Cronan received his BA in Biology (1965) from California State University, Northridge and his PhD (1968) in Molecular Biology from the University of California, Irvine. As a graduate student with Daniel Wulff, he defined the lipids of Escherichia coli and their metabolic inter-conversions. As a postdoctoral fellow with P. Roy Vagelos at Washington University Medical School he isolated and characterized mutants in fatty acid and phospholipid synthesis. He was an Assistant and Associate Professor in the Department of Molecular Biophysics and Biochemistry at Yale before moving to the University of Illinois at Urbana-Champaign as Professor of Microbiology in 1978.

Research Interests

John Cronan's laboratory is interested in the diversity of lipid synthetic pathways in bacteria. Although some enzymes of fatty acid synthesis are very strongly conserved, others show remarkable diversity. Unsaturated fatty acid synthesis and the last step of the canonical fatty acid synthesis cycle both show significant differences in the enzyme proteins utilized and their enzymatic mechanisms. Other interests are in the synthesis and attachment of the fatty acid-derived cofactors, biotin and lipoic acid. Multiple pathways are evident for both cofactors, although not yet clearly understood. Finally the laboratory studies the synthesis of various fatty acid containing signaling molecules used by bacterial species to coordinate gene expression in response to environmental changes.

Membership Type


Election Year


Primary Section

Section 44: Microbial Biology

Secondary Section

Section 21: Biochemistry