Edwin Pozharski (he/him)

Dr. Pozharskiy's area of scientific expertise is structural biology, with a major focus on protein X-ray crystallography. Throughout his career as a protein crystallographer, Dr. Pozharskiy has focused on structural mechanisms of molecular recognition in a range of biomolecular systems, including small molecules, protein-DNA, and protein-protein interactions. He has also contributed to methodological aspects of protein crystallography, including computational methods, structure validation, and crystallization methods. As a molecular biophysicist, Dr. Pozharskiy has expertise in membrane biophysics and protein thermodynamics, including the study of cationic lipids and their DNA complexes. He utilizes a variety of biophysical techniques, such as dynamic light scattering, protein fluorescence and fluorescence anisotropy, differential scanning fluorimetry, and isothermal titration calorimetry.

As Structural Biology co-Section Leader of the Center for Biomolecular Therapeutics (CBT), Dr. Pozharskiy is involved in various projects focused on structure-based drug design against therapeutic targets related to cancer, diabetes, and infectious disease. He is also involved in a recent joint initiative by IBBR partner institutions to establish research capabilities in single-particle cryoelectron microscopy.

CURRENT RESEARCH

Structural studies of DNA recognition by transcription factors and enzymes

Dr. Pozharskiy’s work on the molecular recognition of DNA by protein molecules includes structural studies of the nickel-dependent transcription factor NikR from Helicobacter pylori. This protein is essential for the bacterium’s ability to survive acidic environments during colonization, as it activates a secreted urease enzyme that is capable of lowering local pH. Previous studies in collaboration with Sara Michel, Professor, Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, have revealed the unique mode of metal binding by this protein. A recently solved crystal structure of the NikR/DNA complex explains the evolutionary mechanism of this transcription factor’s broad specificity to multiple DNA targets.

Another area of research includes structural studies of DNA binding and the evolutionary underpinnings of substrate recognition by human thymine specific DNA glycosylase, an essential enzyme in DNA repair and modification arising in epigenetic context. This work is a collaboration with Alexander Drohat, Professor, Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine.

Structural studies of binary toxin from Clostridium difficile

Clostridium difficile is an opportunistic human pathogen. A recently emerging, highly virulent strain of this bacterium is characterized by the expression of binary toxin CDT, in addition to two canonical C. difficile toxins, TcdA and TcdB. A team-based project in the CBT currently aims to develop novel treatments against this toxin. In collaboration with Amédée des Georges, Assistant Professor of Chemistry & Biochemistry, City College of New York, efforts are currently underway to structurally characterize this binary toxin using single-particle cryoelectron microscopy, focusing on the large oligomeric cell binding component. The enzymatic component of the binary toxin is being targeted for drug design using protein crystallography.