I work to understand and characterize novel microbial ultrastructure. My work employs electron cryotomography, a type of electron microscopy that produces 3D images of intact cells in a near-native, “frozen-hydrated” state. This is a powerful tool for investigating subcellular ultrastructures in vivo and at a macromolecular resolution (3-4nm). I also value the intersection between the scientific research and social justice and prioritize work on structures that have human health or environmental implications.
New Bacterial Structures
In collaboration with the Jensen Lab at Caltech, we analyzed over 15,000 3D images of 88 bacterial species. We discovered several novel structures, including new appendages, nanospheres, filaments, bundles, chains, meshes, tubes, and vesicles. This work will not only promote new investigations into these structures and their functions, but has also shown us that there is still much to be learned about bacteria. Since its publication, this work has been featured as a spotlight article and on the cover of the Journal of Bacteriology, on NPR’s Academic Minute, and in news articles.
ESCRT – scission by spiraling filaments
ESCRT (Endosomal Sorting Complex Required for Transport) is a protein complex that drives membrane scission in cytokinesis and vacuolar sorting, but gets hijacked by RNA viruses like HIV. By imaging dividing archaeal cells and purified protein assemblies, I observed spiraling filaments attached to the membrane. Together with crystal structure fitting, we proposed the spiraling hourglass model.
HIV Capsid Formation – Curled Sheet Model
With high-resolution 3D images of HIV capsids, we observed seams and some misshapen capsids that looked like rolled sheets. Together with computer simulation experiments, we proposed the curled sheet model in which the capsid proteins first form a sheet that curls in on itself to form a fullerene cone. This structural information is important for future drug development to block HIV maturation.
Uncharacterized bacterial structures revealed by electron cryotomography.
Dobro MJ, Oikonomou CM, Piper A, Cohen J, Guo K, Jensen T, Tadayon J, Donermeyer J, Park Y, Solis BA, Kjær A, Jewett AI, McDowall AW, Chen S, Chang YW, Shi J, Subramanian P, Iancu CV, Li Z, Briegel A, Tocheva EI, Pilhofer M, Jensen GJ.
Journal of Bacteriology. 199(17) 1-14. 2017.
**Selected by Journal of Bacteriology as spotlight article and cover image for the issue.**
The Structure, Function and Roles of the Archaeal ESCRT Apparatus.
Samson RY, Dobro MJ, Jensen GJ, Bell SD.
Springer. 84:357-377. 2017.
Embryo development inside female salamander (Ambystoma jeffersonianum-laterale) prior to egg laying.
Charney ND, Castorino JJ, Dobro MJ, Steely SL.
PLoS One. 9(3) 2014.
Electron cryotomography of ESCRT assemblies and dividing Sulfolobus cells suggests that spiraling filaments are involved in membrane scission.
Dobro MJ, Samson RY, Yu Z, McCullough J, Ding HJ, Chong PL, Bell SD, Jensen GJ.
Molecular Biology of the Cell. 24(15) 2319-27. 2013.
Unclosed HIV-1 capsids suggest a curled sheet model of assembly.
Yu Z^, Dobro MJ^, Woodward CL, Levandovsky A, Danielson CM, Sandrin V, Shi J, Aiken C, Zandi R, Hope TJ, Jensen GJ.
Journal of Molecular Biology. 425(1) 112-23. 2012.
^Authors contributed equally to work
Structural diversity of bacterial flagellar motors.
Chen S, Beeby M, Murphy GE, Leadbetter JR, Hendrixson DR, Briegel A, Li Z, Shi J, Tocheva EI, Müller A, Dobro MJ, Jensen GJ.
The EMBO Journal. 30(14) 2972-81. 2011.
Electron cryotomography of bacterial cells.
Chen S, McDowall A, Dobro MJ, Briegel A, Ladinsky M, Shi J, Tocheva EI, Beeby M, Pilhofer M, Ding HJ, Li Z, Gan L, Morris DM, Jensen GJ.
Journal of Visualized Experiments. (39) 2010.
Plunge freezing for electron cryomicroscopy.
Dobro MJ, Melanson LA, Jensen GJ, McDowall AW.
Methods in Enzymology. 481(3) 63-82. 2010.
Have some questions about my research? Looking to book a speaking engagement? Looking to collaborate? Want to join the Plasmodium Consortium? Please send me a message and I'll get back to you ASAP. Thanks.