Understanding metal-dissolving enzymes


The availability of metals such as iron and manganese in the soil is essential for life, but these metals are often trapped in insoluble and inaccessible minerals. To release them microorganisms use them to respire in place of oxygen, however this requires a reaction to occur outside the cell surface. In Geobacter sulfurreducens a dedicated mineral reductase called PgcA is responsible for directly catalysing the reduction of iron oxides, but the process is not understood. This project aims to characterise the properties of this enzyme and understand how biological organisms are able to interact and alter insoluble minerals. The techniques involved include small angle X-ray scattering (SAXS) and michalis-menten kinetics adapted to analyse insoluble substrates.

This PhD will be supervised by Dr Tom Clarke in collaboration with Prof. Julea Butt. Informal enquiries can be made to Dr Tom Clarke (t.clarke@uea.ac.uk).


Li DB, Edwards MJ, Blake AW, Newton-Payne SE, Piper SEH, Jenner LP, Sokol KP, Reisner E, Van Wonderen JH, Clarke TA, Butt JN.
His/Met heme ligation in the PioA outer membrane cytochrome enabling light-driven extracellular electron transfer by Rhodopseudomonas palustris TIE-1.
Nanotechnology. 2020 May 13;31(35):354002.

Edwards MJ, White GF, Butt JN, Richardson DJ, Clarke TA.
The Crystal Structure of a Biological Insulated Transmembrane Molecular Wire.
Cell. 2020 181:665-673.e10.

Edwards MJ, Richardson DJ, Paquete CM, Clarke TA.
Role of multiheme cytochromes involved in extracellular anaerobic respiration in bacteria
Protein Sci. 2019