Stephen Charles Kowalczykowski ("Steve K") is a Distinguished Professor o
Microbiology and Molecular Genetics
at th
University of California at Davis
His research focuses on the biochemistry and molecular biology of

DNA repair DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA da ...

and

homologous recombination Homologous recombination is a type of genetic recombination in which genetic information is exchanged between two similar or identical molecules of double-stranded or single-stranded nucleic acids (usually DNA as in cellular organisms but may ...

. His lab combines fluorescence microscopy, optical trapping and

microfluidics Microfluidics refers to the behavior, precise control, and manipulation of fluids that are geometrically constrained to a small scale (typically sub-millimeter) at which surface forces dominate volumetric forces. It is a multidisciplinary field th ...

to manipulate and visualize single molecules of DNA and the

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

s involved in processing and repairing DNA. He calls this scientific approach, "visual biochemistry". Stephen Kowalczykowski was elected to the American Society for Arts and Science in 2005, th
National Academy of Sciences
in 2007 and was a Harvey Society Lecturer at Rockefeller University in 2012.

Education and career

Stephen Kowalczykowski studied chemistry (B.S.) at Rensselaer Polytechnic Institute in 1972 and earned his Ph.D. in Chemistry/Biochemistry at

Georgetown University Georgetown University is a private university, private research university in the Georgetown (Washington, D.C.), Georgetown neighborhood of Washington, D.C. Founded by Bishop John Carroll (archbishop of Baltimore), John Carroll in 1789 as Georg ...

in 1976. His dissertation title was "Physical-Chemistry studies of Sickle Cell Hemoglobin." He then worked as a postdoctoral researcher wit
Dr. Peter von Hippel
at the

University of Oregon The University of Oregon (UO, U of O or Oregon) is a public research university in Eugene, Oregon. Founded in 1876, the institution is well known for its strong ties to the sports apparel and marketing firm Nike, Inc, and its co-founder, billion ...

Health Sciences Institute, where he began studying the physical chemistry of protein-nucleic interactions. He began his academic research career at Northwestern University Medical School in 1981 and later moved to the University of California at Davis in 1991. He is one of the world's foremost experts on

RecA RecA is a 38 kilodalton protein essential for the repair and maintenance of DNA. A RecA structural and functional homolog has been found in every species in which one has been seriously sought and serves as an archetype for this class of homolog ...

, the defining member of a ubiquitous class of DNA strand-exchange proteins that are essential for homologous recombination, a pathway that maintains genomic integrity by repairing broken DNA. His lab has made significant contributions to the fields of

, homologous recombination and the biophysics of DNA helicases.

Scientific contributions

A few of his lab's notable scientific contributions include the structural and molecular mechanism of DNA end resection by RecBCD (''E. coli'') and DNA2-Sgs1-RPA and regulatory stimulation by Top3-Rmi1 and Mre11-Rad50-Xrs2 (''S. cerevisiae''), the kinetics of

filament nucleation and growth and regulation by RecFOR (''E. coli''), the purification and molecular mechanism of the human breast cancer susceptibility gene BRCA2 (humans), the mechanism of the Holliday junction dissolution by the

Bloom's Syndrome Bloom syndrome (often abbreviated as BS in literature) is a rare autosome, autosomal recessive genetic disorder characterized by short stature, predisposition to the development of cancer, and genomic instability. BS is caused by mutations in the ' ...

helicase (BLM) homologue, Sgs1 (''S. cerevisiae''), and the mechanism of the 3-dimensional homology search catalyzed by

(''E. coli'').

Publications

Research publications on Pubmed

References

{{DEFAULTSORT:Kowalczykowski, Stephen American microbiologists American molecular biologists 21st-century American biologists University of California, Davis faculty Georgetown University alumni Rensselaer Polytechnic Institute alumni Members of the United States National Academy of Sciences Fellows of the American Academy of Arts and Sciences Living people Year of birth missing (living people)