Insights in Enzyme Research

Substrate locking promotes dimer-dimer docking of an enzyme antibiotic target

EuroSciCon Congress on Enzymology and Molecular Biology
August 13-14, 2018 Paris ,France

Matthew A Perugini, Sarah C Atkinson, Con Dogovski, Kathleen Wood, Michael D W Griffin, Michael A Gorman, Lilian Hor, Cyril F Reboul, Ashley M Buckle, Joachim Wuttke, Michael W Parker and Renwick C J Dobson

La Trobe University, Melbourne, Australia Bio21 Institute, University of Melbourne, Victoria, Australia Monash University, Clayton, Australia Australian Nuclear Science & Technology Organisation, New South Wales, Australia St. Vincents Institute of Medical Research, Victoria, Australia JCNS-Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Juelich GmbH, Garching, Germany University of Canterbury, Christchurch, New Zealand

Posters & Accepted Abstracts: Insights Enzyme Res

DOI: 10.21767/2573-4466-C1-003

Abstract

Protein dynamics manifested through structural flexibility play a central role in the function of biological molecules. Here we explore the substrate-mediated change in protein flexibility of an enzyme antibiotic target, Clostridium botulinum dihydrodipicolinate synthase (DHDPS). We demonstrate that the substrate, pyruvate, stabilizes the more active dimer-of-dimers or tetrameric form of the enzyme. Surprisingly, there is little difference between the crystal structures of apo and substratebound DHDPS, suggesting protein dynamics may be important. Neutron and small angle X-ray scattering experiments were used to probe substrate-induced dynamics on the sub-second timescale, but no significant changes were observed. We have therefore developed a simple technique, coined Protein Dynamics-Mass Spectrometry (ProD-MS), which enables measurement of time-dependent alkylation of cysteine residues. ProD-MS together with X-ray crystallography and analytical ultracentrifugation analyses indicates that pyruvate locks the conformation of the dimer that promotes docking to the more active tetrameric form, offering new insight into ligand-mediated stabilization of multimeric enzymes.

Biography

E-mail:

M.Perugini@latrobe.edu.au