Jochen Zimmer
University of Virginia, VA·Biochemistry
Cells of every kind coat themselves in long sugar chains. These complex carbohydrates stiffen the cell boundary, help manage water balance, form the scaffolding between cells, and carry signals between them.
- Fields
Biochemistry
Biophysics
Microbiology & Immunology
- Topics
complex carbohydrates
polysaccharide secretion
cellulose synthase
- Grants
- 1 known grant, through Dec 2026
What they work on
- Determine how cellulose biosynthesis is controlled in enterobacteria such as E. coli, building on the lab's structures of the supramolecular cellulose synthase complex that both polymerizes and secretes this glucose chain.
- Define how cellulose is chemically modified with phosphoethanolamine in the periplasm, the space between a bacterium's inner and outer membranes, and how the modified polymer crosses the outer membrane.
- Reconstitute O antigen translocation in vitro with purified WzmWzt, the ATP-powered ABC transporter that pumps lipopolysaccharide sugar chains across the inner membrane, to establish its biochemical mechanism.
- Capture structural snapshots of WzmWzt during substrate translocation by X-ray crystallography and cryo-electron microscopy, testing how an ABC transporter moves a long polymer rather than a small molecule.
More about the research
Biologists understand reasonably well how proteins are pushed across or inserted into membranes, but the equivalent question for sugar polymers — which range from acidic and water-loving to greasy and insoluble — is largely unanswered, even though these polymers matter in both normal physiology and disease. This research asks, at the level of individual atoms, how big carbohydrate polymers are built and then delivered to the outside of the cell. The approach combines structural biology with biochemistry, glycobiology (the study of sugars in biology), biophysics, bioinformatics, and molecular biology, using microbial, viral, plant, and vertebrate systems to compare secretion machines that work in fundamentally different ways.
Why it matters
The sugar coats studied here protect bacteria inside a host and hold biofilms together, and biofilms cause the large majority of hospital-acquired infections. Working out the molecular machinery that builds and exports these polymers could expose points of attack for new antibacterial drugs, and understanding how cellulose is made and modified could also inform the engineering of carbohydrate-based biomaterials.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Michael Stephen Trent
University of Georgia, GA·Microbiology & Immunology
Develop an analytical tool that measures LPS molecules in transit, and combine it with mass spectrometry of the enzyme LpxC and LPS precursors to determine how the YejM-YciM system controls LPS production in E. coli.
David Cafiso
University of Virginia, VA·Biophysics
Test models of how TonB-dependent transporters such as BtuB, the vitamin B12 transporter, move nutrients across the E. coli outer membrane, using site-directed spin labeling and EPR spectroscopy on active proteins.
Maria Lara-Tejero
Yale University, CT·Microbiology & Immunology
Determine the structure of the Salmonella type III secretion sorting platform, the part of the injectisome inside the bacterium, using cryo-EM and cryo-electron tomography.
The school
University of Virginia: 43 labs on PI Pages, $814M a year on research, 413 research doctorates a year.
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