Lab group – August 2018
Top row from left: Anton Alenko, Vadim Patsalo, Matthew J. Salie, Olivier Duss, John Hammond
Middle row from left: Luigi D’Ascenzo, Lili K. Doerfel, Yisong Deng, Galina Stepanyuk, Anna Popova
Bottom row from left: Katrina Schreiber, James R. Williamson, Jessica Rabuck-Gibbons, Ning Li


James R. Williamson, Ph.D. – Professor

For those interested in joining our Lab, please visit the OPEN POSITIONS page for more information!


Luigi D’Ascenzo, Ph.D.

I am currently working on realizing a “molecular movie” of the ribosome biogenesis, integrating simulations and 3D modelling with experimental data. In parallel, I am developing novel tools for mass spectrometry data analysis with heavy isotope labelling, focusing on the investigation of modifications in ribosomal RNA and on proteomics analysis of prokaryotes.
LinkedIn | ResearchGate
| Google Scholar | Twitter

Lili K. Doerfel, Ph.D.

I am studying ribosome assembly in vitro. This allows to severely perturb ribosome assembly e.g. by deleting essential proteins or adding inhibitory molecules and thus enables to explore the plasticity of the assembly pathway and its regulatory network. Using a combination of a functional assay, quantitative mass spectrometry and single particle cryo-electron microscopy the structure of assembly intermediates can be correlated with the r-protein content and the activity of the particle. Moreover, I aim to correlate co-transcriptional rRNA processing and rRNA folding to the sequential binding of ribosomal proteins and the transient action of ribosome assembly factors thereby achieving kinetic insight into the assembly process.

Olivier Duss, Ph.D.

I am interested how transcription of the ribosomal RNA is coupled to ribosome assembly. Using single-molecule microscopy, I am setting up an approach to study how single nascent RNA molecules bind to ribosomal proteins in real-time.
LinkedIn | ResearchGate

Ning Li, Ph.D.

Currently I’m working on the project about function of assembly cofactor in vivo during ribosome biogenesis in E. coli. Using mass spectrometry technology, I can analyze the ribosome protein composition and RNA modification level in cofactor depleted strain. The 3-D structure of ribosome from cofactor depleted strain will be clarified by cryo-EM method. Cofactors’ function will be analyzed through comparing protein composition and structure with ribosome from wild type strain.
CV | LinkedIn

Vadim Patsalo, Ph.D.

I aim to understand and quantitatively predict bacterial resource allocation. Cells execute such gene-expression strategies during both steady-state growth and dynamic adaptations to changing environments, such as the sudden onset of stress. Measuring physiological, metabolic, and gene-expression parameters, we work to establish a systematic biophysical comprehension of the cell.

Anna Popova, Ph.D.

I am particularly fond of rRNA modifications! All different kinds, found in bacteria, yeast, and human cells. Using modern mass spectrometry tools, I can identify and quantify relative abundance of RNA modifications in mature ribosomes and the intermediates. This quantitative approach proved to be effective in understanding modifications as part of the ribosome biogenesis process.
LinkedIn | ResearchGate

Jessica Rabuck-Gibbons, Ph.D.

I am interested in exploring the structure of heterogeneous RNA/protein complexes in vivo and expanding biophysical characterization methodologies. Currently, I am working on understanding ribosome biogenesis in vivo. After depleting E. coli of a ribosomal protein of interested, I use a combination of quantitative mass spectrometry with isotope labeling and single particle cryo-electron microscopy to understand the composition and structure of the ribosome assembly intermediates.
LinkedIn | Twitter

Matthew J. Salie, Ph.D.

My current project is a proteomic study of prokaryotic physiology. I am using heavy isotope labeling and mass spectrometry to quantify global protein abundance and degradation rates in E. coli cultures and have set up a chemostat to impose and precisely control growth rate limitations.
LinkedIn | ResearchGate

Galina Stepanyuk, Ph.D.

I’m interested in the RNA-protein and protein-protein interactions and their structural and functional implications in bacterial ribosomal assembly. My current projects involve variety of biophysical, biochemical, labeling and visualization techniques, as well as protein and RNA engineering and design.
LinkedIn | ResearchGate | Google Scholar


    John Hammond, Ph.D., Staff Scientist

I am interested in the assembly, function, and structure of viral/host ribonucleoprotein complexes. Of late, we have been studying the assembly of a nuclear export complex required for HIV-1 replication, as well as understanding the assembly of the HIV-1 virus. This work uses a variety of biochemical, biophysical and cellular biology techniques to provide a universal structural and functional view of these RNP processes.

Lincoln Scott, Ph.D., Visiting Investigator

I am interested in the chemo-enzymatic synthesis of isotopically labeled nucleotides and nucleotide analogs. These compounds are used in a variety of NMR and mass spectrometry based biophysical studies of RNA and RNA-protein complexes. This work has led to the formation of Cassia LLC, a company that prepares isotopically labeled primary metabolites for the biophysical research community.
Cassia, LLC
LinkedIn | ResearchGate

Yisong Deng, Graduate Student

I am interested in the in vivo assembly process of HIV virus. Using pulse labeling and quantitative mass spectrometry, I aim to define the order and dynamics of the assembly process. Other biochemical, biophysical and imaging techniques are also used to provide information regarding the composition and property of the assembly intermediates.

Katrina Schreiber, Administrative Staff

Analytical and detail-oriented professional with experience coordinating, planning, and supporting daily operational and administrative functions within the Williamson Laboratory and in support of Dr. Williamson’s executive obligations. I come from a lengthy background of management roles in research and healthcare, with 16+ combined years at TSRI, and plan to continue my lifelong pursuit of assisting my colleagues, so they can focus on what they do best…science!