Dr John Crosby

Research in our group involves the use of a broad range of techniques including protein expression and purification, enzyme kinetics, and the accurate mass analysis of these large biomolecules by electrospray mass spectrometry. By isolating individual enzymes and establishing structural details, enzyme specificities, and kinetic characteristics we hope to understand fully how biosynthetic pathways are controlled.

Enzymology of Polyketide Biosynthesis

Many biologically active compounds are synthesised in nature via the polyketide pathway. The core of all polyketide structures is similar, and is assembled by a multicomponent enzyme system, the polyketide synthase (PKS). The synthase controls a series of cycles of reactions in which simple building blocks (usually acetate) are linked via carbon bond formation, followed by a highly specific sequence of modifying reactions. We aim to understand how the PKS controls the exact sequence of chemical steps involved in the biosynthesis of antibiotics.