Protein Crystallography

Group Leader

Tassos Papageorgiou, PhD
Adjunct Professor in Biochemistry and Structural Biology
tassos.papageorgiou [at]

Contact Information

Phone: +358 2 333 8012
FAX: +358 2 333 8000
Mailing address: Turku Centre for Biotechnology,
Biocity Turku, 5th floor, Tykistokatu 6, Turku 20521


We use X-ray crystallography as the major tool to provide detailed information on the structure and function of biological molecules. Knowledge of the 3-dimensional structure of proteins is essential to understand at the atomic level how proteins function or, in the case of diseases, how they malfunction. Our current projects include:

  • Pathogen-host interactions. The complexity of pathogen-host interactions is investigated in our group by looking at proteins involved in stress protection and adhesion. Understanding the mechanistic details of bacterial survival under various forms of stress could be useful in the design of novel ways to combat or prevent disease. Peroxide resistance, for example, plays a major role in the survival of bacteria and the spread of disease. We are particularly interested in a class of ferritin-like proteins that are able to bind and oxidize iron. By combining site-directed mutagenesis, protein structure determination and X-ray absorption spectroscopy we aim to provide a more comprehensive view of the role and function of ferritin-like proteins in bacterial survival. Adhesion offers alternative solutions to combat antibiotic resistance and we are currently working on newly identified proteins to provide structural insights for the design of new antibacterial strategies.
  • Signalling proteins. Signalling is a biological process that depends strongly on molecular recognition and protein-protein interactions. Our aim is to understand the structural aspects of this process at atomic level and to use the obtained structural information for the development of novel ways of therapeutic intervention in disease.
  • Enzyme structure and function. Understanding enzyme adaptation in various environmental conditions will enable the design of better performance tailor-made enzymes for use in biomedicine, biotechnology, and green chemistry. Structure determination at high/atomic resolution combined with directed evolution, mutagenesis studies, thermal denaturation analysis and other biophysical techniques is expected to give a better picture of the studied proteins/enzymes under various conditions. Thus, for protein stability studies we use a multidisciplinary approach that includes, apart from X-ray crystallography, several biophysical methods such as fluorescence spectroscopy, microcalorimetry, circular dichroism, and enzyme kinetic assays.
  • Radiation damage. The use of synchrotron radiation has been central to all our structural studies. By analyzing data collected in synchrotrons followed by close inspection of the resultant protein structures at atomic resolution we have been able to study more fundamental problems in crystallography, such as radiation damage. The latter arises from the interaction of powerful X-rays with biological specimens and has become a critical issue in modern data collection strategies. Understanding this process and finding ways to prevent it is important for the elucidation of more accurate protein structures.

Our protein structure and chemistry core facility pages can be found here

Selected Recent Publications

  • Chronopoulou, E.G., Papageorgiou, A.C., Ataya, F., Nianiou-Obeidat, I., Madesis, P. & Labrou, N.E. (2018) Expanding the plant GSTome through directed evolution: DNA shuffling for the generation of new synthetic enzymes with engineered catalytic and binding properties. Front Plant Sci (accepted)
  • Theoharaki, C., Chronopoulou, E., Clachakis, D., Ataya, F.S., Giannopoulos, P., Mavrikou, S., Skopelitou, K., Papageorgiou, A.C. & Labrou, N.E. (2018) Delineation of the functional and structural properties of the glutathione transferase family from the plant pathogen Erwinia carotovora. Funct. Integr. Genomics  Pubmed
  • Papageorgiou, A.C. (2018) X-ray crystallography in structure-function characterization of therapeutic enzymes (in press)
  • Li, D.-C & Papageorgiou, A.C. (2018). Cellulases from thermophilic fungi: Recent insights and biotechnological applications (in press)
  • Haataja, S., Verma, P., Fu, O., Papageorgiou, A.C., Pöysti, S., Pieters, R.J., Nilsson, U.J., Finne, J. (2018) Rationally designed chemically modified glycodendrimer inhibits Streptococcus suis adhesin SadP at picomolar concentrations Chem. Eur. J. 24, 1905-1912 Pubmed
  • Perveen, S., Rashid, N., Tang, X.-F.,  Imanaka, T. and PapageorgiouA. C.  (2017) Anthranilate phosphoribosyltransferase from the hyperthermophillic archaeon Thermococcus kodakarensis shows maximum activity with zinc and forms a unique dimeric structure FEBS Open Bio. 7,1217-1230 Pubmed
  • Papageorgiou, A.C., Chen, J. & Li, D.C. (2017) Crystal structure and biological implications of a glycoside hydrolase family 55 ß-1,3-glucanase from Chaetomium thermophilum. Biochim. Biophys. Acta. 2017 1865(8):1030-1038 Pubmed
  • Kellici, T., Mavromoustakos, T., Jendrossek, D. & Papageorgiou, A.C. (2017) Crystal structure analysis, covalent docking and molecular dynamics calculations reveal a conformational switch in PhaZ7 PHB depolymerase. Proteins: Struct. Funct. Bioinform. Pubmed
  • Chatzikonstantinou, M., Vlachakis, D., Papageorgiou, L., Papageorgiou, A.C. & Labrou, N.E. (2017) The glutathione transferase family of Chlamydomonas reinhardtii: Identification and characterization of novel sigma class-like enzymes. Algal Research 24, 237-250 DOI
  • Axarli, I., Muleta, A.W., Chronopoulou, E.G., Papageorgiou, A.C. & Labrou, N.E. (2017) Directed Evolution of Glutathione Transferases Towards a Selective Glutathione-Binding Site and Improved Oxidative Stability. Biochim Biophys Acta 1861, 3416-3428 Pubmed
  • Skopelitou, K., Muleta, A.W., Papageorgiou, A.C., Pavli, O., Flemetakis, E., Skaracis, G.N. & Labrou. N.E. (2017) Characterization and functional analysis of a recombinant Tau-class glutathione transferase GmGSTU2-2 from Glycine max. Intern J. Biol. Macromol. 94:802-812 Pubmed
  • Perveen, S., Rashid, N. & Papageorgiou, A.C. (2016) Crystal structure of a phosphoribosyl anthranilate isomerase from the hyperthermophilic archaeon Thermococcus kodakaraensis. Acta Cryst F 72:804-812 Pubmed
  • Lundahl, M., Cunha, G., Rojo, E., Orelma, H., Papageorgiou, A.C., Arboleda, J. & Rojas, O. (2016) Strength and Water Interactions of Cellulose I Filaments Wet-Spun from Cellulose Nanofibril Hydrogels. Sci. Rep. 6:30695 Pubmed
  • Blazevits, O., Mideksa, Y., Solman, M., Ligabue, A., Ariotti, N., Nakhaeizadeh, H., Fansa,E., Papageorgiou, A.C., Wittinghofer, A., Ahmadian, M., & Abankwa, D. (2016). Galectin-1 dimers can scaffold Raf-effectors to increase H-ras nanoclustering. Sci. Rep. 6:24165 Pubmed
  • Axarli, I., Muleta, A.W., Vlachakis, D., Kossida, S., Kotzia, G., Maltezos, A., Dhavala, P., Papageorgiou, A.C. & Labrou, N.E. (2016). Directed evolution of tau class glutathione transferases reveals a site that regulates catalytic efficiency and masks cooperativity. Biochem. J473, 559-570 Pubmed
  • Poudel, N., Pfannstiel, J., Simon, O., Walter, N., Papageorgiou, A.C. & Jendrossek, D. (2015)Pseudomonas aeruginosa isohexenyl glutaconyl-CoA hydratase (AtuE) is upregulated in citronellate-grown cells and belongs to the crotonase family. Appl. Environm. Microbiol. 81, 6558-6566 Pubmed
  • Papageorgiou, A.C. &  Li, D.-C. (2015) Expression, purification and crystallization of a family 55 ß-1,3-glucanase from Chaetomium thermophilumActa Cryst F 71:680-683 Pubmed
  • Labrou, N.E., Papageorgiou, A.C., Pavli, O.  & Flemetakis, E. (2015) Plant GSTome: Structure and functional role in xenome network and plant stress response. Curr. Opin. Biotechn.32: 186-194 Pubmed
  • Skopelitou, K., Muleta, A., Papageorgiou, A.C., Chronopoulou, E. & Labrou, N.E. (2015) Catalytic features and crystal structure of a tau class glutathione transferase from Glycine max specifically upregulated in response to soybean mosaic virus infections. Biochim. Biophys. Acta 1854: 166-177 Pubmed