John E Cronan

John E Cronan

Office: (217) 333-7919
Lab: (217) 244-3466
Fax: (217) 244-6697

Mail to: Microbiology
601 S Goodwin Ave
Urbana, IL 61801

Professor of Microbiology
Professor of Biochemistry
Microbiology Alumni Professor

Research Topics

Biofuels, Enzymology, Genetics, Membrane Biology, Microbial Physiology, Regulation of Gene Expression

Disease Research Interests

Infectious Diseases


B.A. (Biology), California State University, 1965
Ph.D. (Molecular Biology), University of California, Irvine, 1968
Postdoctoral (Biochemistry), Washington University School of Medicine, 1968-1970

Genetic approaches to regulation of lipid metabolism; synthesis and attachment of biotin and lipoic acid

My laboratory works in two main areas-regulation of lipid metabolism and synthesis and attachment of fatty acid related enzyme cofactors. In both areas, the organism studied is Escherichia coli due to its sophisticated genetics and simple lipid composition. However we also study a variety of gram positive bacteria. We have studied mechanisms that regulate the composition of the membrane phospholipids of E. coli and are currently concerned how this organism regulates lipid synthesis such that it is neither "fat nor lean." Although, E. coli is the paradigm for bacterial lipid synthesis there are bacteria that are missing genes that are in essential for E. coli growth.  We are in process of figuring out which proteins these bacteria use in place of those used by E. coli.  This has practical consequences because bacterial fatty acid synthesis is the target of several newly developed antibiotics.  We have found that two key coenzymes, how lipoic acid and biotin, found in all three domains of life require the fatty acid synthetic pathway for their synthesis.   We have determined how E. coli makes these coenzymes and are now expanding into the pathways found in other bacteria.

Figure 1.


Member, National Academy of Sciences
Fellow, American Academy of Microbiology
University Scholar
Microbiology Alumni Endowed Professorship

Representative Publications

Cao X, Hong Y, Zhu L, Hu Yand Cronan JE3.Development and retention of a primordial moonlighting pathway of protein modification in the absence of selection presents a puzzle. Proc Natl Acad Sci U S A. (2018) 115:647-655. PMCID: PMC5789953 Hu Z, Dong H, Ma JC, Yu Y, Li KH, Guo QQ, Zhang C, Zhang WB, Cao X, Cronan JE and Wang, H (2018) Novel Xanthomonas campestris long-chain-specific 3-oxoacyl-acyl carrier protein reductase involved in diffusible signal factor synthesis. mBio 9: pii: e00596-18. PMCID: PMC941067.

Cao X, Zhu L, Song X, Hu, Z and Cronan JE (2018) Protein moonlighting elucidates the essential human pathway catalyzing lipoic acid assembly on its cognate enzymes. Proc Natl Acad Sci U S A.115:E7063-E7072. PMCID: PMC6064980

Cao X, Koch T, Steffens L, Finkensieper J, Zigann R, Cronan JE and Dahl C (2018) Lipoate-binding proteins and specific lipoate-protein ligases in microbial sulfur oxidation reveal an atypical role for an old cofactor. eLife. 2018; 7: e37439. PMCID: PMC6067

Kondakova, T. and John E. Cronan (2019) Transcriptional regulation of fatty acid cis-trans isomerization in the solvent-tolerant soil bacterium, Pseudomonas putida F1. Environ. Microbiol.21:1659-1676. PMID:30702193

Zhu, L, Zou, Q., Cao X and Cronan JE (2019) Enterococcus faecalis encodes an atypical auxiliary acyl carrier protein required for efficient regulation of fatty acid synthesis by exogenous fatty acids. MBio. 2019 May 7;10(3). pii: e00577-19. doi: 10.1128/mBio.00577-19. PMID 31064829

Srinivas, S. and J E. Cronan (2019) Coping with inadvertent lysis of Escherichia coli cultures: strains resistant to lysogeny and infection by the stealthy lysogenic phage Φ80. Biotechnol Bioeng. 116:1820-1826. doi: 10.1002/bit.26971. PMID 30882900

Srinivas, S. Hu, Z. and J E. Cronan (2019) Escherichia coli vectors having stringently repressible replication origins allow streamlining of CRISPR/Cas9 gene editing. Plasmid 103:53-62. doi: 10.1016/j.plasmid.2019.04.004. PMID 31047915.

Kondakova, T. and John E. Cronan (2019) A novel synthesis of trans-unsaturated fatty acids by the Gram-positive commensal bacterium Enterococcus faecalis FA2-2. Chem Phys Lipids 222:23-35 doi: 10.1016/j.chemphyslip.2019.04.010. PMID: 30236800

Cronan, J. E. (2016) Assembly of Lipoic Acid on its Cognate Enzymes: An Extraordinary and Essential Biosynthetic Pathway. Mol. Biol. Rev 80: 429-450. PMID:27074917. PMCID: PMC4867368.

Cronan, J. E. (2018) Advances in synthesis of biotin and assembly of lipoic acid. Curr Opin Chem Biol. 47:60-66. PMCID: PMC6289770

Complete Publications List