Stephen Kowalczykowski

Stephen Kowalczykowski

Position Title
Distinguished Professor

Department of Microbiology and Molecular Genetics, College of Biological Sciences

Briggs Hall 310

Research Interests

Biochemical mechanisms of DNA recombination and single-molecule visualization of protein-DNA interactions

Biochemical mechanism of genetic recombination and DNA repair; DNA helicases and motor proteins; Physical and structural aspects of protein-nucleic acid interactions; Single-molecule biophysics; Nanotechnology; Cancer biology.

Grad Group Affiliations

  • Biochemistry, Molecular, Cellular and Developmental Biology
  • Biophysics
  • Integrative Genetics and Genomics
  • Microbiology

Specialties / Focus

  • Biochemistry
  • Cancer Biology
  • Chromosome Biology
  • Chromosome Dynamics and Nuclear Function
  • Computational Biology
  • DNA Repair
  • Dynamics and Biophysical Engineering
  • Molecular Genetics
  • Molecular Medicine
  • Molecular Microbiology
  • Spectroscopy and Imaging


  • MIC 276 Adv Concepts DNA Metab, Spring
  • MIC 263 Principles of Protein-Nucleic Acid Interactions, Winter


  • Briggs Hall 306
    • Naofumi Handa, Theetha Pavankumar
  • Briggs Hall 304
    • Nastaran Hadizadeh, Steven Gore, Galina Drofyak, Valentin Taryanik
  • Briggs Hall 303
    • Ichiro Amitani, Pham Minh Tuan,
  • Briggs Hall 307
    • Taeho Kim, Katsumi Morimatsu, Artem Lada

Honors and Awards

  • Phi Lambda Upsilon, Chemical Honor Society, 1971
  • Sigma Xi, 1974
  • American Cancer Society Postdoctoral Fellowship, 1977-1980
  • American Cancer Society Junior Faculty Research Award, 1983-1986
  • National Institutes of Health MERIT Award, 2000-2010
  • American Association for the Advancement of Science, Fellow, 2001
  • American Academy of Microbiology, Fellow, 2003
  • University of California, Davis, Academic Senate Faculty Research Lecture Award, 2005
  • American Academy of Arts and Sciences, Fellow, 2005
  • National Academy of Sciences, Member, 2007
  • University of California, Davis, College of Biological Sciences, Faculty Research Award, 2011
  • Michael J. Gait Award, Nucleic Acids Group of the Royal Society of Chemistry, 2012
  • Harvey Lecture, The Harvey Society, 2012

    Professional Societies

    • American Society for Biochemistry and Molecular Biology, FASEB
    • American Chemical Society, Division of Biological Chemistry
    • American Society for Microbiology
    • American Association for the Advancement of Sciences
    • Biophysical Society


    • 1972 BS Chemistry Rensselaer Polytechnic Institute
    • 1976 PhD Chemistry (Biochemistry) Georgetown University


    Graham, J.E., Marians, K.J., and Kowalczykowski, S.C. (2017). Independent and Stochastic Action of DNA Polymerases in the Replisome. Cell, 169, 1201-1213.e17 (DOI: PMID: 28622507; PMCID: PMC5548433

    Kowalczykowski, S.C. (2015). An overview of the molecular mechanisms of recombinational DNA repair. Cold Spring Harb. Perspect. Biol., 7. 10.1101/cshperspect.a016410

    Wang, A.T., Kim, T., Wagner, J.E., Conti, B.A., Lach, F.P., Huang, A.L., Molina, H., Sanborn, E.M., Zierhut, H., Cornes, B.K., Abhyankar, A., Sougnez, C., Gabriel, S. B., Auerbach, A. D., Kowalczykowski, S. C., and Smogorzewska, A. (2015). A dominant mutation in human RAD51 reveals its function in DNA interstrand crosslink repair independent of homologous recombination. Mol. Cell, 59, 478-490

    Morimatsu, K., and Kowalczykowski, S.C. (2014). RecQ helicase and RecJ nuclease provide complementary functions to resect DNA for homologous recombination. Proc. Natl. Acad. Sci. U.S.A. 111, E5133-5142

    Liu, B., Baskin, R.J., and Kowalczykowski, S.C. (2013). DNA Unwinding heterogeneity by RecBCD results from static molecules able to equilibrate. Nature, 500, 482–485

    Paeschke, K., Bochman, M.L., Garcia, P.D., Cejka, P., Friedman, K.L., Kowalczykowski, S.C., and Zakian, V.A. (2013). Pif1 family helicases suppress genome instability at G-quadruplex motifs. Nature, 497, 458-62

    Forget, A.L., Dombrowski, C.C., Amitani, I., and Kowalczykowski, S.C. (2013). Exploring protein-DNA interactions in 3D using in situ construction, manipulation, and visualization of individual DNA-dumbbells with optical traps, microfluidics, and fluorescence microscopy. Nature Protoc., 8, 525-538

    Bell, J.C., Plank, J.L., Dombrowski, C.C., and Kowalczykowski, S.C. (2012). Direct imaging of RecA nucleation and growth on single molecules of SSB-coated ssDNA. Nature, 491, 274-278.

    Forget, A.L. and Kowalczykowski, S.C. (2012). Single-molecule imaging of DNA pairing by RecA reveals a 3-dimensional homology search. Nature, 482, 423–427.

    Nimonkar, A.V., Genschel, J., Kinoshita, E., Polaczek, P., Campbell, J.L., Wyman, C., Modrich, P., and Kowalczykowski, S.C. (2011). BLM-DNA2-RPA-MRN and EXO1-BLM-RPA-MRN constitute two DNA end resection machineries for human DNA-break repair. Genes & Dev., 25 350-362.

    Cejka, P., Cannavo, E., Polaczek, P., Masuda-Sasa, T., Pokharel, S., Campbell, J.L., and Kowalczykowski, S.C. (2010). DNA end resection by Dna2-Sgs1-RPA and its stimulation by Top3-Rmi1 and Mre11-Rad50-Xrs2. Nature, 467, 112-116

    Jensen, R.B., Carreira, A., and Kowalczykowski, S.C. (2010). Purified human BRCA2 stimulates RAD51-mediated recombination. Nature, 467, 678-683

    Complete List of Published Work: