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Previous research

I completed my PhD in the lab of Prof. Colin Robinson where my research focused on understanding the mechanism of Tat-dependent protein translocation using Escherichia coli and Bacillus subtilis as model organisms for Gram-negative and Gram-positive bacteria.

The Tat (Twin-Arginine Translocation) pathway is responsible for the translocation of fully folded proteins across the bacterial plasma membrane and has been most widely studied using E. coli as a model organism. In Gram-negative bacteria 3 integral membrane proteins (TatA, TatB, and TatC) are required for translocation. These 3 proteins are organised into two major types of complex within the membrane, a substrate binding TatABC complex and seperate TatA complexes that are thought to serve as the channel through which substrates can cross the membrane.

The Tat pathway in Gram-positive bacteria exhibits some interesting differences to Gram-negative systems, most notably the absence of a separate TatB component. This suggested possible differences in translocation mechanism to Gram-negative bacteria and my work focussed on studying the B. subtilis Tat pathway to try and address this hypothesis. My work has resulted in a number of important findings and these have been published in the journal articles listed.

More recently I have developed an interest in the Tat pathway in Cyanobacteria where proteins are targeted to both the plasma and thylakoid membranes. How proteins are sorted to each membrane is not currently known. Linking in with my current research the Tat pathway has been found to be inportant for the biosynthesis of metalloproteins in cyanobacteria, by compartmentalising protein folding to the cytoplasm.