Thomas M. Harper, Cynthia M. June, Magdalena A. Taracila, Robert A. Bonomo, Rachel A. Powers, David A. Leonard. Multiple substitutions lead to increased loop flexibility and expanded specificity in Acinetobacter baumannii carbapenemase OXA-239. Biochem J. 2018 Jan 11;475(1):273-288. doi: 10.1042/BCJ20170702.

Whole article available online.



Thomas M. Harper and Dylan J. Taatjes. The complex structure and function of Mediator. J Biol Chem. 2017 Sep 14. pii: jbc.R117.794438. doi: 10.1074/jbc.R117.794438.

Whole article available online.



Curriculum Vitae


BS       Grand Valley State University, Chemistry                                               April 2015

Graduated Cum Laude

Biochemistry Emphasis

MS      University of Colorado Boulder, Biochemistry                                November 2018

Graduated Cum Laude


Honors and Awards

MAS4/STEM Scholarship                                                                                           2012

Awarded scholarship by National Science Foundation.


Research Experience

University of Colorado Boulder, Boulder, CO                                           2015 to 2018

Graduate Student, Taatjes Lab

  • Utilized cryo-electron microscopy to characterize the structure and function of the CDK8 module of the Mediator complex.
  • Published a review paper in Journal of Biological Chemistry.

Grand Valley State University, Grand Rapids, MI                                        2013 to 2015

Undergraduate Researcher, Leonard Lab

  • Employed x-ray crystallography and steady-state kinetics to study a clinical variant of the OXA-23 beta-lactamase enzyme.
  • Obtained three x-ray structures of the variant, dubbed OXA-239, with three different beta-lactam drugs bound to the active sites (PDB codes 5WI3, 5WI7, 5WIB).
  • Published a research paper of results in Biochemical Journal.


Teaching Experience

Davenport University, Grand Rapids, MI                                            Sep 2019 to Present

Tutor, Chemistry, Biology, Algebra, Statistics

  • Tutor for General Chemistry I & II, covering periodic trends, physical & chemical properties, quantum mechanics, thermodynamics, acids & bases, and stoichiometry.
  • Tutor for Algebra I & II, covering functions, polynomials, quadratics, factoring, radicals, graphing.
  • Tutor for Introductory Statistics, covering probability, permutations and combinations, random variables, confidence intervals, and hypothesis testing.

University of Colorado Boulder, Boulder, CO                                Jan 2016 to May 2016

Teaching Assistant, Chemistry and Biochemistry

  • Acted as teaching assistant for General Chemistry I for winter/spring semester, an undergraduate course for major and non-majors, covering periodic trends, physical and chemical properties, quantum mechanics, thermodynamics, acids and bases, and stoichiometry.
  • Oversaw two laboratory and two recitation sections per week, proctored exams, graded lab reports every week.


University of Colorado Boulder, Boulder, CO                               Sept 2015 to Dec 2015

Teaching Assistant, Chemistry and Biochemistry

  • Acted as teaching assistant for Biochemistry II for fall semester, an undergraduate course averaging 40 students per semester, covering metabolism of carbohydrates, fatty acids, amino acids, and nucleic acids.
  • Oversaw two recitation sections per week, proctored exams, and graded quizzes and exams.

Grand Valley State University, Grand Rapids, MI                         Sept 2014 to Dec 2014

Teaching Assistant, Chemistry

  • Acted as teaching assistant for CHM 232 laboratory section, an undergraduate course for non-majors.
  • Oversaw one lab section per week.


Grand Rapids Community College, Grand Rapids, MI                 Dec 2010 to May 2012

Tutor, Math and Chemistry

  • Tutored students in Algebra I and II and in General Chemistry I and II.



Journal Publications in Press

Harper, T.M., Taatjes, D.J., “The Complex Structure and Function of Mediator,” Journal of Biological Chemistry, DOI: 10.1074/jbc.R117.794438.

Harper, T.M., June, C.M., Taracila, M.A., Bonomo, R.A., Powers, R.A., and Leonard, D.M., “Multiple Substitutions Lead to Increased Loop Flexibility and Expanded Specificity in Acinetobacter baumanni Carbapenemase OXA-239,” Biochemical Journal, DOI: 10.1042/BCJ20170702.


Thomas Harper, Incarnate: Existence. Kindle Direct Publishing, 2014.

Thomas Harper, Incarnate: Essence. Kindle Direct Publishing, 2019.

Thomas Harper, Incarnate: Schism. Kindle Direct Publishing, 2020.

Presentations and Invited Lectures

Poster Presentation, “A triple-substitution clinical variant of OXA-23 carbapenemase from Acinetobacter baumannii shows increased activity toward cephalosporins and aztreonam,” 250th National Meeting of the American Chemical Society, Boston MA, August 19, 2015.

Poster Presentation, “Characterization of the Carbapenemase OXA-239,” 34th Midwest Enzyme Chemistry Conference, Chicago Illinois, September 27, 2014.