Professor Jon R Sayers, FSB

Professor of Functional Genomics

Professor JR Sayers

Department of Infection and Immunity
Henry Wellcome Laboratories for Medical Research
L Floor
The University of Sheffield Medical School
Beech Hill Rd
Sheffield S10 2RX

Tel: +44 (0)114 271 3027
Fax: +44 (0)114 226 8898
Secretary - Jean Lazenby
Tel: +44 (0)114 271 2237


I teach graduate classes in biochemistry, protein/DNA sequence analysis, protein engineering of novel therapeutics and biotechnology. I studied Chemistry at the University of Birmingham, obtaining my B.Sc. in 1983 where I went on to gain a Ph.D. (1986) in the Nucleic Acids Groups directed by Prof. Stan Jones and Prof. Dick Walker. Thesis title; Synthesis of Nucleoside Analogues. In 1986 I joined the Max-Planck-Institut for Experimental Medicine, Gottingen, Germany under Prof. Fritz Eckstein as a postdoctoral researcher where I studied restriction endonuclease-DNA interactions and helped develop a widely used system for site-directed mutagenesis (the 'phosphorothioate approach'). I also became interested in flap endonucleases, or 5'-3' exonucleases. In 1991 I moved to a Lectureship in the Biochemistry Department at the University of Wales, Bangor, UK, where I established a research group working on various aspects of molecular recognition. Projects included work on novel phage T5 proteins, a schistosomal protease (in collaboration with Dr. Mike Doenhoff), genetic variability of Haemophilus influenzae (in collaboration with Dr. Tony Howard, PHLS Cardiff), generation of new binding proteins and flap endonucleases. I moved to Sheffield in 1995, was promoted to Senior Lecturer in 1997, to a Readership in 1999 and a personal chair in 2006. I have developed an interest in proteins secreted by Gram negative bacterial pathogens and how they interact with the host. We use a wide range of molecular and cell biological and biophysical techniques to unravel the detail of such interactions aided by close collaboration with structural biologists in Sheffield and the United States.  I was elected as a Fellow of the Society of Biology in 2013.

In 2001 I become a director and co-founder of Asterion Ltd., a biotech spin-off company (see Asterion Ltd.)

I have written an article for "The Biochemist" describing the trials and tribulations of an academic involved in the setting up of a spin-out company. It can be found under 'downloads'.

Research Interests

The group is involved in four main areas:

  • Molecular mechanisms involved in protein:DNA interactions.
  • Microbial proteases, pathogenesis and the host response.
  • Novel applications of biotechnology to biomedical research and drug development.
  • Structure-based drug design.

Ongoing topics include the following:

Mechanistic Studies on 5'-3' Exonucleases

A novel helical arch discovered in a 5'-3' exonuclease could explain how this class of essential replicative enzymes digest their nucleic acids substrates. See Ceska, Sayers, Stier & Suck (1996) Nature, 382, 90-93.

These enzymes are involved in replication of the lagging strand during DNA synthesis and in repair of DNA damage. Some members possess structure-specific endonuclease activity as well as exonuclease and RNase H activities. We have shown that a member of this important class of enzymes contains a novel DNA-binding motif, the helical arch (see above picture of the T5 exonuclease). We are using site-directed mutagenesis, crystallography and kinetic studies to determine how these complicated enzymes function. We have cloned and expressed a number of exonucleases from bacteria including the human pathogen Haemophilus influenzae. In collaboration with Dr. Dietrich Suck and Dr. Tom Ceska at the EMBL (Heidelberg) a structural model is emerging for this interesting group of enzymes. This work is funded by the BBSRC, The Wellcome Trust and the White Roses Consortium.

Protein-DNA Recognition

Many important biological processes such as gene expression are regulated by proteins binding to specific DNA sequences. We are studying novel DNA-binding proteins from viruses and pathogenic bacteria. We have chosen proteins with no sequence homologues in the databases. Such proteins are thus unique and studying how they recognize their target sequences should provide new insights into molecular recognition processes. This work is funded by the Bardhan Trust for Educational Research.

Significance of IgA1 Proteases in Pathogenic Neisseria meningitidis and Haemophilus influenzae

We have discovered a strong link between carriage of gene containing a highly variable domain and pathogenesis in these two meningitis-causing organisms. Collaborative work is underway with Dr. Tony Howard (PHLS, Bangor) and Professor Robert Read (Infection & Immunity, Sheffield). We have recently reported data demonstrating that pathogenic strains of Neisseria meningitidis produce higher levels of an enzyme capable of destroying human antibodies. The protease attacks IgA1, a major component of the mucosal immune system. This work has been funded by The Meningitis Research Foundation and the Colin Beattie Memorial Fund and is currently supported by the Medical Research Council.

Immunogenicity of a Schistosomal Protease.

Around 200,000 people die each year as a result of infection with S. mansoni. In a collaboration with Dr. Mike Doenhoff, University of Wales, we have expressed a recombinant protease from S. mansoni and are studying its antigenicity.

Teaching Interests

I teach graduate-level biochemistry, molecular & structural biology, bioinformatics and biotechnology in relation to biomedical research and drug discovery.

Professional Activities

Key Publications

  1. Anstey-Gilbert CS, Hemsworth GR, Flemming CS, Hodskinson MR, Zhang J, Sedelnikova SE, Stillman TJ, Sayers JR, Artymiuk PJ.  The structure of Escherichia coli ExoIX - implications for DNA binding and catalysis in flap endonucleases.  Nucleic Acids Res. 2013 Jul 2. in press doi: 10.1093/nar/gkt591.
  2. Wong IN, Sayers JR, Sanders CM. Characterization of an unusual bipolar helicase encoded by bacteriophage T5. Nucleic Acids Res. 2013, 41, 4587-600.
  3. Ross R, Artymiuk P, Sayers J.  Growth hormone fusion proteins. 2012, Granted US Patent No. 8,293,709.
  4. Tomlinson CG, Syson K, Sengerová B, Atack JM, Sayers JR, Swanson L, Tainer JA,Williams NH, Grasby JA. Neutralizing mutations of carboxylates that bind metal 2 in t5 flap endonuclease result in an enzyme that still requires two metal ions. J Biol Chem. 2011 Sep 2;286(35):30878-87.
  5. Xie P & Sayers JR. A model for transition of 5'-nuclease domain of DNA polymerase I from inert to active modes. PLoS One. 2011 Jan 14;6(1):e16213.
  6. Sengerová B, Tomlinson C, Atack JM, Williams R, Sayers JR, Williams NH, Grasby JA.  Brønsted analysis and rate-limiting steps for the T5 flap endonuclease catalyzed hydrolysis of exonucleolytic substrates. Biochemistry. 2010 Sep
  7. Ferrandis E, Pradhananga SL, Touvay C, Kinoshita C, Wilkinson IR, Stafford K, Wu Z, Strasburger C, Sayers JR, Artymiuk PJ, Ross RJ.  Immunogenicity, toxicology, pharmacokinetics and pharmacodynamics of growth hormone ligand-receptor fusions.  Clin Sci (Lond). 2010 Aug 17;119(11):483-91.
  8. Ross R, Sayers J, Artymiuk P.  Cytokine polypeptides and antibodies containing a signal sequence for the attachment of glycosylphosphatidylinositol, 2009, Granted US Patent No. 7625998.
  9. Ross R, Sayers J, Artymiuk P.  Modified growth hormone fusion polypeptides, 2009, Granted US Patent No. 7524649.
  10. Allen LM, Hodskinson MR, Sayers JR.  Active site substitutions delineate distinct classes of eubacterial flap endonuclease. Biochem J. 2009 Mar 1;418(2):285-92.
  11. Syson K, Tomlinson C, Chapados BR, Sayers JR, Tainer JA, Williams NH, Grasby JA.  Three metal ions participate in the reaction catalyzed by T5 flap endonuclease. J. Biol. Chem. 2008, 283; 28741-28746.
  12. Wilkinson IR, Ferrandis E, Artymiuk PJ, Teillot M, Soulard C, Touvay C, Pradhananga SL, Justice S, Wu Z, Leung KC, Strasburger CJ, Sayers JR, Ross RJ. A ligand-receptor fusion of growth hormone forms a dimer and is a potent long-acting agonist. Nat Med. 2007, 13; 1108-13.
  13. Vitovski S, Phillips JS, Sayers JR, Croucher PI.  Investigating the interaction between osteoprotegerin and rankl or trail: Evidence for a pivotal role for osteoprotegerin in regulating two distinct pathways. J Biol Chem. 2007, 282(43):31601-9.
  14. Hodskinson MR, Allen LM, Thomson DP, Sayers JR.  Molecular interactions of Escherichia coli ExoIX and identification of its associated 3'-5' exonuclease activity. Nucleic Acids Res. 2007, 35; 4094-102.
  15. Williams R, Sengerova B, Osborne S, Syson K, Ault S, Kilgour A, Chapados BR, Tainer JA, Sayers JR, Grasby JA.  Comparison of the catalytic parameters and reaction specificities of a phage and an archaeal flap endonuclease.  J Mol Biol. 2007, 371; 34-48.
  16. Vitovski S, Sayers JR. Relaxed cleavage specificity of an immunoglobulin A1 protease from Neisseria meningitidis. Infection & Immunity, 2007, 75; 2875-85.
  17. Smith P, Fallon RE, Mangan NE, Walsh CM, Saraiva M, Sayers JR, McKenzie AN, Alcami A, Fallon PG. Schistosoma mansoni secretes a chemokine binding protein with antiinflammatory activity. J Exp Med. 2005 202:1319-25.
  18. Parsons HK, Vitovski S, Sayers JR. Immunoglobulin A1 proteases: a structure-function update. Biochem Soc Trans. 2004 32:1130-2.
  19. Smith P, Walsh CM, Mangan NE, Fallon RE, Sayers JR, McKenzie AN, Fallon PG. Schistosoma mansoni worms induce anergy of T cells via selective up-regulation of programmed death ligand 1 on macrophages. J Immunol. 2004 173:1240-8.
  20. Feng M, Patel P, Dervan JJ, Ceska T, Suck D, Haq I, Sayers JR.  Roles of divalent metal ions in flap endonuclease-substrate interactions.  Nature Structural & Molecular Biology 2004, 11: 450 - 456.
  21. Tock MR, Frary E, Sayers JR, Grasby JA.  Dynamic evidence for metal ion catalysis in the reaction mediated by a flap endonuclease.  EMBO J. 2003 22:995-1004.
  22. Patel D, Tock MR, Frary E, Feng M, Pickering TJ, Grasby JA, Sayers JR.  A conserved tyrosine residue aids ternary complex formation, but not catalysis, in phage T5 flap endonuclease.  J Mol Biol. 2002 320(5):1025-35.
  23. Dervan JJ, Feng M, Patel D, Grasby JA, Artymiuk PJ, Ceska TA, Sayers JR.  Interactions of mutant and wild-type flap endonucleases with oligonucleotide substrates suggest an alternative model of DNA binding.  Proc Natl Acad Sci USA. 2002 99(13):8542-7.
  24. Vitovski S, Dunkin KT, Howard AJ, Sayers JR.  Nontypeable Haemophilus influenzae in carriage and disease: a difference in IgA1 protease activity levels.  J. American Med. Assoc. JAMA. 2002 287(13):1699-705.
  25. Garforth SJ, Patel D, Feng M, Sayers JR.  Unusually wide co-factor tolerance in a metalloenzyme; divalent metal ions modulate endo-exonuclease activity in T5 exonuclease. Nucleic Acids Res. 2001 Jul 1;29(13):2772-9.
  26. Vitovski S, Read RC, Sayers JR.  Invasive isolates of Neisseria meningitidis possess enhanced immunoglobulin A1 protease activity compared to colonizing strains.  FASEB J. 1999 Feb;13(2):331-7.
  27. Garforth SJ, Ceska TA, Suck D, Sayers JR.  Mutagenesis of conserved lysine residues in bacteriophage T5 5'-3' exonuclease suggests separate mechanisms of endo-and exonucleolytic cleavage.  Proc Natl Acad Sci U S A. 1999 Jan 5;96(1):38-43.
  28. Smith MC, Burns N, Sayers JR, Sorrell JA, Casjens SR, Hendrix RW.  Bacteriophage collagen. Science 1998 Mar 20;279(5358):1834.