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Nathan Field

A current PhD student in Warwick's School of Life Sciences.

Thanks for visiting my e-Portfolio.

My main supervisor is Dr. David Roper (Structural Biology) and I am co-supervised in the Department of Chemistry by Prof. Tim Bugg (Chemical Biology).

I'm interested in the 3D structures and functions of a family of enzymes involved in the degradation of aromatic compounds, which have potential applications in breaking down persistent pollutant chemicals as well as producing useful biochemicals from plant sources.

Techniques I use include: protein expression in E. coli; protein purification by FPLC; protein X-ray crystallography; enzymatic synthesis of small molecule substrates; UV-visible absorbance spectroscopy; circular dichroism spectropolarimetry; isothermal titration calorimetry.

Scroll down for a technical research abstract, or if you're not a scientist, have a look at my "non-specialists" page.

I am funded by the BBSRC Life Sciences Doctoral Training Grant.

I'm ! - Take a look at my LinkedIn profile.

Aromatic degradation and a novel enzyme fold

Enzymatic pathways for the breakdown of aromatic compounds are almost universal in bacteria. One pathway of interest is the E. coli homoprotocatechuate (HPC) degradation pathway, comprising 7 enzymatic steps. Each enzyme has a solved X-ray crystal structure. Three catalytic domains - the two domains of HpcE, a bifunctional decarboxylase/isomerase, and the single-domain hydratase HpcG - share a common structural element, designated the FAH fold, from fumarylacetoacetate hydrolase. FAH is a mammalian enzyme involved in tyrosine metabolism, mutations in which cause hereditary tyrosinemia type I. A number of functionally uncharacterised proteins have also been classed as having a FAH fold through structural genomics initiatives. This project aims to explore the catalytic flexibility of the fold, starting with HpcG and HpcE. Initial work has focused on site-directed mutagenesis of HpcG and a functional homolog in a related pathway, MhpD, to extend their substrate specificities and illustrate the flexibility of the FAH fold. Activity assays for these enzymes have first required the synthesis of their respective substrates. Obtaining crystal structures of HpcG and MhpD with bound cofactors, substrates and inhibitors will provide additional mechanistic insight. Further work will include functional assignment of selected orphan bacterial, yeast and human FAH-fold proteins through ligand screening strategies.

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Nathan Field

Nathan dot Field at warwick dot ac dot uk