... understanding life in molecular detail

Dr Roman Tuma

RNA virus, reovirus assembly, single molecule biophysics, Sec translocon mechanism, bacteriochlorophyll nanostructures

We apply combination of advanced biophysical techniques to study self-assembly and function of large macromolecular complexes such as viruses, Sec translocon, helicases and chromatin remodelling ATPases. Key biological processes that are studied in our group: RNA packaging and segment assortment in dsRNA viruses of the Reoviridae family; chromatin remodelling by CHD4; mechanism and dynamics of hexameric helicases and SecA driven polypeptide translocation across membranes. We also use self-assembly of bacterial photosynthetic pigments to create hybrid quantum dot nanostructures for applications in synthetic biology and nanophotonics.

Current major projects include:
  • Assembly and nucleic acid packaging in RNA viruses
  • Mechanism of ATP-driven chromatin remodelling
  • Single molecule biophysics
  • Sec translocon mechanism
  • Self-assembly of bacteriochlorophyll nanostructures

Research areas: virus assembly, mechanisms and regulation of molecular machines, single molecule spectroscopy, self-assembling nanostructures

Research projects:

Assembly of dsRNA viruses

Our research is focused on assembly of dsRNA viruses of the Reoviridae family (e.g. major pathogens like human rotavirus and avian reovirus). These viruses have up to 12 different RNA segments packaged in each virion. Virus assembly takes place inside dense viral inclusion bodies (viroplasms) inside infected cells and is poorly understood. We are studying structure and interaction of proteins within viroplasms and delineate RNA-RNA and RNA-protein interactions that are essential for the segment assortment. 


Mechano-chemical coupling in cooperative molecular machines

Molecular motors convert chemical energy (usually from ATP hydrolysis) into mechanical work. They play essential roles in nucleic acid replication (helicases) and general translocation (Sec translocon). We are elucidating the principles of coupling between ATP hydrolysis and mechanical motion. i.e. mechano-chemical coupling. In collaborative and interdisciplinary projects we employ an interdisciplinary approach based on molecular biology (site-directed mutagenesis), structural and computational biology (X-ray crystallography, hydrogen-deuterium exchange, molecular dynamics) and single molecule techniques (single molecule fluorescence). Our machines of interest are hexameric RNA helicases and Sec translocon. The later is a multisubunit membrane compolex that mediates export of proteins across plasma membrane.  

Self-assembling nanostructures

We study the structure and self-assembly of pigments in chlorosomes, bacterial light harvesting antennae. The photosynthetic pigments (bacteriochlorophylls) are organized into lamellar aggregates. Similar nanostructures can be self-assembled from purified pigments in vitro and exhibit strong excitonic coupling and fast excitation energy transfer rates. These nano-structured assemblies constitute promising biomaterial for photonic applications and photovoltaic cells.


Detailed research programme                  Close ▲

Reader in Biophysics (Leeds) 2007-present;
MSc (Charles University, Prague) PhD (University o
University of Missouri Alumni Achievement Award

Graduate research assistant (University of Missouri) 1992-1996
Postdoctoral Fellow (University of Alabama at Birmingham) 1996-1999
Group leader (University of Helsinki) 1999-2003
Academy of Finland Fellow (University of Helsinki) 2003-2008

Miall 10.27
School of Molecular and Cellular Biology
0113 343 3080

Selected Publications

  1. Allen WJ, Corey RA, Oatley P, Sessions RB, Baldwin SA, Radford SE, Tuma R, Collinson I (2016) Two-way communication between SecY and SecA suggests a brownian ratchet mechanism for protein translocation. eLife 5, e15598. DOI:10.7554/eLife.15598

  2. Borodavka A, Ault J, Stockley PG, Tuma R (2015) Evidence that avian reovirusσNS is an RNA chaperone: implications for genome segment assortment. Nucleic acids research 43, 7044-7057. DOI:10.1093/nar/gkv639

  3. Patel N, Dykeman EC, Coutts RH, Lomonossoff GP, Rowlands DJ, Phillips SE, Ranson N, Twarock R, Tuma R, Stockley PG (2015)
    Revealing the density of encoded functions in a viral RNA. Proc Natl Acad Sci U S A 112 2227-2232. DOI:10.1073/pnas.1420812112

  4. Sharma A, Leach RN, Gell C, Zhang N, Burrows PC, Shepherd DA, Wigneshweraraj S, Smith DA, Zhang X, Buck M, Stockley PG, Tuma R (2014) Domain movements of the enhancer-dependent sigma factor drive DNA delivery into the RNA polymerase active site: insights from single molecule studies. Nucleic Acids Res 42 5177-5190. DOI:10.1093/nar/gku146