Department of Biology & Biochemistry
Susan Crennell

Senior Lecturer

4 South 0.26


Tel: +44 (0) 1225 38  4302


Dr Susan Crennell 


Current Research

Glycoside hydrolases, enzymes which cleave glycoside bonds to produce two smaller sugars, are widespread in nature and have correspondingly broad use in biotechnology. Cellulases, glycoside hydrolases that break down cellulose, are used in a broad range of industrial processes, for example clarifying fruit juices, textile processing and a rapidly expanding interest in the possibility of extracting ethanol from waste products of the food industry (stalks, husks etc.) to use as a renewable biofuel.

Thermostability: As part of the Centre for Extremophile Research, I am interested in the structural basis for protein thermostability, comparing proteins from hyperthermophilic organisms to their homologues from organisms growing at room temperature or below.

A recent glycoside hydrolase example is the biotechnologically-important cellulase from Rhodothermus marinus which has a half life of more than 2.5 hours at 90°C, (research in collaboration with Eva Nordberg Karlsson, Lund University). In complex with inhibitors or flash-frozen with substrate, X-ray crystal structures of this cellulase have revealed details of substrate binding mechanisms as well as thermophilic adaptation.  

This enzyme shows a number of thermophilic adaptations, the most obvious being a large increase in the number of surface electrostatic interactions (ion pairs) over mesophilic counterparts.

Complementary techniques used to investigate structure and function include X-ray scattering (e.g. for the structure of Rhodothermus marinus xylanase, see the CER pages) and computational analysis. We have used the University of Houston Brownian Dynamics program (UHBD) to quantify the contribution of ion pairs to thermostability of citrate synthase and are testing these predictions in the laboratory by altering the number of ion pairs using site directed mutagenesis.

Pathogenesis: Studies of other glycoside hydrolases such as cell-wall-degrading enzymes secreted by Stagonospora nodorum, a wheat pathogen, understanding of which will aid disease control (in collaboration with Prof Richard Cooper) and enzymes with potential for intervention in human disease (in collaboration with Dr Andrew Watts, Pharmacy & Pharmacology) are at a less advanced stage.


Extance, J., Danson, M. J. and Crennell, S. J., 2016. Structure of an acetylating aldehyde dehydrogenase from the thermophilic ethanologen Geobacillus thermoglucosidasius. Protein Science, 25 (11), pp. 2045-2053.

Buddrus, L., Andrews, E. S. V., Leak, D. J., Danson, M. J., Arcus, V. L. and Crennell, S. J., 2016. Crystal structure of pyruvate decarboxylase from Zymobacter palmae. Acta Crystallographica Section F:Structural Biology Communications, 72 (9), pp. 700-706.

Tratt, J., Crennell, S., Qi, B., Scott, R. and Doughty, J., 2016. Identifying the wall-degrading enzymes responsible for microspore release from the pollen tetrad in Arabidopsis thaliana. In: 24th International Congress on Sexual Plant Reproduction, 2016-03-18 - 2016-03-25, University of Arizona.

Marrott, N., Marshall, J. J. T., Svergun, D. I., Crennell, S., Hough, D. W., Van Den Elsen, J. and Danson, M., 2014. Why are the 2-oxoacid dehydrogenase complexes so large? Generation of an active trimeric complex. Biochemical Journal, 463 (3), pp. 405-412.

Wells, S. A., Crennell, S. J. and Danson, M. J., 2014. Structures of mesophilic and extremophilic citrate synthases reveal rigidity and flexibility for function. Proteins: Structure, Function, and Bioinformatics, 82 (10), pp. 2657-2670.

Espina Silva, G., Eley, K., Pompidor, G., Schneider, T. R., Crennell, S. J. and Danson, M. J., 2014. A novel β-xylosidase structure from Geobacillus thermoglucosidasius:The first crystal structure of a glycoside hydrolase family GH52 enzyme reveals unpredicted similarity to other glycoside hydrolase folds. Acta Crystallographica Section D-Biological Crystallography, 70 (5), pp. 1366-1374.

Extance, J., Crennell, S. J., Eley, K., Cripps, R., Hough, D. W. and Danson, M. J., 2013. Structure of a bifunctional alcohol dehydrogenase involved in bioethanol generation in Geobacillus thermoglucosidasius. Acta Crystallographica Section D-Biological Crystallography, 69 (10), pp. 2104-2115.

Posner, M. G., Upadhyay, A., Crennell, S., Watson, A. J. A., Dorus, S., Danson, M. J. and Bagby, S., 2013. Post-translational modification in the archaea: structural characterization of multi-enzyme complex lipoylation. Biochemical Journal, 449 (2), pp. 415-425.

Marrott, N. L., Marshall, J. J. T., Svergun, D. I., Crennell, S. J., Hough, D. W., Danson, M. J. and van den Elsen, J. M. H., 2012. The catalytic core of an archaeal 2-oxoacid dehydrogenase multienzyme complex is a 42-mer protein assembly. FEBS Journal, 279 (5), pp. 713-723.

Moore, V., Kanu, A., Byron, O., Campbell, G., Danson, M. J., Hough, D. W. and Crennell, S. J., 2011. Contribution of inter-subunit interactions to the thermostability of Pyrococcus furiosus citrate synthase. Extremophiles, 15 (3), pp. 327-336.

Clark, E. A., Crennell, S., Upadhyay, A., Zozulya, A. V., Mackay, J. D., Svergun, D. I., Bagby, S. and van den Elsen, J. M. H., 2011. A structural basis for Staphylococcal complement subversion:X-ray structure of the complement-binding domain of Staphylococcus aureus protein Sbi in complex with ligand C3d. Molecular Immunology, 48 (4), pp. 452-462.

Royer, S. F., Haslett, L., Crennell, S. J., Hough, D. W., Danson, M. J. and Bull, S. D., 2010. Structurally informed site-directed mutagenesis of a stereochemically promiscuous aldolase to afford stereochemically complementary biocatalysts. Journal of the American Chemical Society, 132 (33), pp. 11753-11758.

Pelat, T., Bedouelle, H., Rees, A. R., Crennell, S., Lefranc, M. P. and Thullier, P., 2008. Germline humanization of a non-human primate antibody that neutralizes the anthrax toxin, by in vitro and in silico engineering. Journal of Molecular Biology, 384 (5), pp. 1400-1407.

This list was generated on Sat Oct 21 13:04:26 2017 IST.

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