Thomas Tomasiak

Assistant Professor, Chemistry and Biochemistry

Degrees and Appointments

  • 2004, Biomedical Sciences, Grand Valley State University
  • 2011, PhD, Vanderbilt University (Prof. Tina Iverson)
  • 2010 - 2015 Postdoctoral Researcher, University of California - San Francisco (UCSF) (Prof. Robert Stroud)
  • 2015-2017 Research Specialist, University of California - San Francisco (UCSF)
  • 2018 - Present, Assistant Professor University of Arizona

Fields of Study: Biochemistry

Research Specialities: Biophysics, Metabolism, Signaling, and Regulation, Protein and Membrane Biochemistry, Spectroscopy/Molecular Structure, Structural Biology

Awards and Honors:

  • 2007 Lee Limbird Dissertation Enhancement Award
  • 2015 NIH K99 Pathway to Independence Award


Our bodies face the tremendous task of sorting, organizing, and safely dealing with the millions of small molecules they encounter every day. These chemicals include nutrients, drugs, and toxins with profound implications for our health and for drug design. Our lab focuses on the main systems that our bodies use to recognize and sort these compounds, especially transporters from the ATP Binding Cassette (ABC) and Solute Carrier Superfamily (SLC) families using a combination of biochemistry, genetics, and structural biology. These transporters have presented challenges owing to their instability once extracted from our cells membranes. The formulation of new lipid isolation systems, new analytical methods, and powerful new structural biology tools, especially powerful new electron microscopes, have cracked these problems open and present an exciting new forefront in understanding fundamental biology as well as in drug design.

The main focus of our group is to understand the molecular details of how transporter-drug interactions take place. My previous work used then-unproven fast readout direct-electron detection cameras on electron microscopes to “unblur” images that previously suffered beam induced motions. The 2017 Nobel Prize in Chemistry was awarded in this area of the cryo-EM field and our lab combines these techniques with cutting edge membrane protein stabilization techniques to understand the difficult question of how transporter polyspecificity is achieved and how we might mitigate the activity of some transporters with therapeutics to fight disease.

1. Nöll A, Thomas C, Herbring V, Zollmann T, Barth K, Mehdipour AR, Tomasiak TM, Brüchert S, Joseph B, Abele R, Oliéric V, Wang M, Diederichs K, Hummer G, Stroud RM, Pos KM, Tampé R. Crystal structure and mechanistic basis of a functional homolog of the antigen transporter TAP. The Proceedings of the National Academy of Sciences. (2017) 114: E438-E447 (PMID:28069938)

2. Kim J*, Wu S*, Tomasiak TM*, Mergel C, Winter MB, Stiller S, Colmanares Y, Tampé R, Stroud RM, Craik CS, Cheng Y. Subnanometer resolution cryo-EM structure of a nucleotide free heterodimeric ABC exporter. Nature (2015) 517: 396 – 400. (PMID: 25363761)
* Equal first author contribution

3. Tomasiak TM, Pedersen BP, Chaudhary S, Rodriguez A, Robles-Colmanares Y, Roe-Zurz Z, Thamminana S, Tessema M, Stroud RM. General qPCR and plate reader methods for rapid optimization of membrane protein purification and crystallization using thermostability assays. Current Protocols In Protein Science (2014) 77: 29.11.1 – 29.11.14. (PMID: 25081745)

4. Monk BC*, Tomasiak TM*, Keniya MV, Huschmann FU, Tyndall JDA, O’Connell III JD, Cannon RD, Finer-Moore J, McDonald J, Rodriquez A, Stroud RM. Architecture of a single membrane spanning cytochrome P450 suggests constraints that orient the catalytic domain relative to a bilayer. The Proceedings of the National Academy of Sciences (2014) 111: 3865 – 3870. (PMCID: PMC3956205)

* Equal first author contribution

Featured on the cover and in additional commentary in PNAS. Pochapsky TC. Examining how enzymes self-organize in a membrane. The Proceedings of the National Academy of Sciences (2014) 111(10): 3659-3660

5. Tomasiak TM, Archuleta TL, Davis T, Ham AJ, McDonald H, Johnston J, Cecchini G, Iverson TM. Geometric restraint drives on- and off-pathway catalysis by the Escherichia coli menaquinol:fumarate reductase. Journal of Biological Chemistry (2011) 286: 3047 – 3056. (PMCID: PMC3024798)

6. Tomasiak TM, Maklashina E, Cecchini G, and Iverson TM. A threonine on the active site loop controls transition state formation in Escherichia coli respiratory complex II. Journal of Biological Chemistry (2008) 283: 15460 – 15468. (PMCID: PMC2397489)