NDSU Crystallographers, Dr. Christopher Colbert and Dr. Sangita Sinha, are featured in RefleXions, the quarterly American Crystallographic Association (ACA) Fall newsletter (http://www.amercrystalassn.org/documents/2013FallNewsWeb.pdf) for their work in protein crystallography presented at the 2013 annual ACA meeting.
Dr. Colbert’s research entitled “Structural Characterization of Pandoraea Pnomenusa B-356 Biphenyl Dioxygenase Reveals Features of a Potent PCB-Degrading enzyme” was highlighted in the BioMac Posters section. In this study Dr. Colbert and his coauthors used information from multiple high-resolution structures to understand the mechanism and specificity of this enzyme and to construct a structure-based classification of this enzyme compared to other Rieske oxygenase proteins. This study led to understanding the superior ability of some enzymes to degrade polychlorinated biphenyls (PCBs), which are important environmental pollutants. Further, based on this information the authors were able to design mutations to improve the reactivity of biphenyl dioxygenase oward a wider variety of PCBs. Dr. Sinha also contributed to this work, which is now published in the journal PLoS One: (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0052550).
Dr. Sinha presented a seminar entitled “Targeting the g-herpesvirus mediated inhibition of autophagy” in the scientific session on Host Pathogen Interactions. g-herpesviruses are cancer-causing viruses that also cause important human diseases like infectious mononucleosis. Dr. Sinha’s work has elucidated the mechanism by which a protein encoded by the g-herpesvirus down-regulates autophagy, a critical cellular degradation pathway that protects the cell from pathogens. This seminar reported recent results obtained by her graduate students Ms. Minfei Su and Ms. Yang Mei, wherein they combined information from cellular and biochemical experiments to develop and test a peptide that selectively inhibits g-herpesvirus down-regulation of autophagy, but does not interfere with normal cellular regulation. The mechanism by which the peptide is bound by the viral protein was elucidated by determining the atomic structure of the viral protein-peptide complex. This peptide could provide a basis for the development of therapeutics targeting g-herpesvirus infections. Dr. Colbert also contributed to this work, which is under review in the journal J. Biol. Chem.