Squire J. Booker

Squire J. Booker

Main Content

  • Howard Hughes Medical Investigator
  • Professor of Chemistry
  • Professor of Biochemistry and Molecular Biology
  • Howard Hughes Medical Investigator
302 Chemistry Building
University Park, PA 16802
(814) 865-8793


  1. B.A. in chemistry, Austin College, 1987
  2. Ph.D. in biochemistry, Massachusetts Institute of Technology, 1994

Honors and Awards:

  1. 2015 Howard Hughes Medical Investigator
  2. 2012 Arthur C. Cope Scholar Award
  3. Presidential Early Career Award in Science and Engineering
  4. NSF Faculty Early Career Award
  5. NIH Postdoctoral Fellow
  6. NSF–NATO Postdoctoral Fellow

Selected Publications:


Warui, D. M., Li, N., Nørgaard, H., Krebs, C., Bollinger, J. M., Jr., Booker, S. J. Detection of formate, rather than carbon monoxide, as the stoichiometric coproduct in conversion of fatty aldehydes to alkanes by a cyanobacterial aldehyde decarbonylase. J. Am. Chem. Soc., 2011, 133, 3316–3319.

Arcinas, A. J., Booker, S. J. Radical break-up, blissful make-up. Nat. Chem. Biol., 2011, 7, 133–134.

Grove, T. L., Benner, J. S., Radle, M. I., Ahlum, J. H., Landgraf, B. J., Krebs, C., Booker, S. J. A radically different mechanism for S-adenosylmethionine-dependent methyltransferases. Science, 2011, 332, 604–607.

Li, N., Nørgaard, H., Warui, D. M., Booker, S. J., Krebs, C., Bollinger, J. M., Jr, Conversion of fatty aldehydes to alka(e)nes and formate by a cyanobacterial aldehyde decarbonylase: Cryptic redox by an unusual dimetal oxygenase. J. Am. Chem. Soc., 2011, 133, 6158–6161

Boal, A. K., Grove, T. L., McLaughlin, M. I., Yennawar, N., Booker, S. J., Rosenzweig, A. C.  Structural basis for methyl transfer by a radical SAM enzyme. Science, 2011, 332, 1089–1092.

Grove, T. L., Radle, M. I., Krebs, C., Booker, S. J. Cfr and RlmN contain a single [4Fe–4S] cluster, which directs two distinct reactivities for S-adenosylmethionine: methyl transfer by SN2 displacement and radical generation. J. Am. Chem. Soc., 2011, 133, 19586–19589.


Krebs, C.*, Bollinger, J. M., Jr.*, Booker, S. J.*  "Cyanobacterial alkane biosynthesis expands the functional and mechanistic repertoire of the "di-iron-carboxylate" proteins,"  Current Opinion Chem. Biol., 2011, 15, 291-303.

Grove, T. L., Ahlum, J. H., Sharma, P., Krebs, C., Booker, S. J. "A consensus mechanism for radical SAM-dependent dhydrogenation? BtrN contains two [4fe-FS] clusters," Biochemistry, 2010, 49, 3783-3785.

Booker, S. J. "Anaerobic functionalization of unactivated C–H bonds," Curr. Opin. Chem. Biol., 2009, 13, 58–73

Saleh, L., Lee, K.-H., Anton, B. P., Madinger, C. L., Benner, J. S. Roberts, R. J. Krebs, C. and Booker, S. J. "Characterization of RimO, a new member of the methylthioltransferase subclass of the radical SAM superfamily," Biochemistry, 2009, 48, 10162–10174.

Matthews, M. L., Neumann, C. S., Miles, L. A., Grove, T. L., Booker, S. J., Krebs, C., Walsh, C. T., Bollinger, J. M. Jr.  "Substrate positioning controls the partition between halogenation and hydroxylation in the aliphatic halogenase, SyrB2," Proc. Natl. Acad. Sci. USA, 2009, 106, 17723–17728.

Saunders, A. H., Griffiths, A. E., Lee, K.-H., Cicchillo, R. M., Tu, L. Stromberg, J. A., Krebs, C., and Booker, S. J. "Characterication of quinolinate synthases from Escherichia coli, Mycobacterium tuberculosis, and Pyrococcus horikoshii indicates that [4Fe-4S] clusters are common cofactors throughout this class of enzymes," Biochemistry, 2008, 47, 10999-1012

Chatterjee, A., Li, S., Zhang, Y., Grove, T. L., Lee, M., Krebs, C., Booker, S. J., Begley, T. P., Ealick, S. E.  "Reconstitution of ThiC in thiamine pyrimidine biosynthesis expands the radical SAM superfamily," Nat. Chem. Biol., 2008, 4, 758-765



Research in the Booker Lab focuses on elucidating the chemical mechanisms by which enzymes containing iron-sulfur clusters catalyze chemical reactions. Most ongoing projects deal with members of the Radical S-adenosylmethionine Superfamily, a diverse group of enzymes that employ radical chemistry to catalyze transformations involved in post-transcriptional and post-translational modifications, cofactor biosynthesis, secondary metabolite biosynthesis, and enzyme activation. Radical SAM enzymes share a [4Fe-4S] cluster cofactor that is used to reductively cleave S-adenosylmethionine and form the 5’-deoxyadenosyl radical, a potent oxidant typically used to abstract a hydrogen atom and initiate radical chemistry on the substrate. These remarkable enzymes utilize this initial shared step to catalyze a wide array of transformations including methylations, sulfur insertions, decarboxylations, and complex rearrangements. Using a combination of biochemical, analytical, structural, and spectroscopic techniques, the Booker Lab works to characterize these complex and intriguing reaction mechanisms to provide insight for applications to human health and disease and gain a greater understanding of how Nature has worked to solve difficult chemical problems.  

Research Interests:


Biochemistry; enzymology; protein chemistry

Chemical Biology