Poster Presentation The 43rd Lorne Conference on Protein Structure and Function 2018

The long and short of DAH7PS: distinct quaternary structures of two type II isozymes from Pseudomonas aeruginosa (#235)

Oliver W Sterritt 1 , Geoffrey B Jameson 2 , Emily J Parker 3
  1. University of Canterbury, Christchurch, CANTERBURY, New Zealand
  2. Institute of Fundamental Sciences, Massey University , Palmerston North, New Zealand
  3. Victoria University of Wellington, Wellington, New Zealand

The shikimate pathway is responsible for the biosynthesis of key aromatic metabolites including the aromatic amino acids phenylalanine, tyrosine, and tryptophan and, in the case of Pseudomonas aeruginosa, the toxic secondary metabolite pyocyanin.


The enzyme 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAH7PS) catalyses the first step of the shikimate pathway and is often subject to feedback inhibition by pathway end products. The allosteric binding sites are generally located in close proximity to the interfaces and, as such, quaternary structure plays a key role in the function and regulation of the enzyme. The presence of structural elements that are additional to the core catalytic domain influences the nature of the quaternary assembly and hence these structural elements are related to the allosteric properties of the enzyme.  


We have solved the structure of two DAH7PS isozymes from P. aeruginosa, revealing for the first time the structure of a short form enzyme that is involved in pyocyanin biosynthesis. These structures illuminate the distinct quaternary assemblies that are likely associated with unique allosteric properties of these enzymes.

  1. Blackmore, N. J., Reichau, S., Jiao, W. T., Hutton, R. D., Baker, E. N., Jameson, G. B., and Parker, E. J. (2013) Journal of Molecular Biology 425, 1582-1592
  2. Jiao, W., Blackmore, N. J., Nazmi, A. R., and Parker, E. J. (2017), PLoS One 12, 21