Browse by author
Lookup NU author(s): Professor Alastair Hawkins
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Dehydroquinate synthase (DHQS) is a potential target for the development of novel broad-spectrum antimicrobial drugs, active against both prokaryotes and lower eukaryotes. Structures have been reported for Aspergillus nidulans DHQS (AnDHQS) in complexes with a range of ligands. Analysis of these AnDHQS structures showed that a large-scale domain movement occurs during the normal catalytic cycle, with a complex series of structural elements propagating substrate binding-induced conformational changes away from the active site to distal locations. Compared to corresponding fungal enzymes, DHQS from bacterial species are both mono-functional and significantly smaller. We have therefore determined the structure of Staphylococcus aureus DHQS (SaDHQS) in five liganded states, allowing comparison of ligand-induced conformational changes and mechanisms of domain closure between fungal and bacterial enzymes. This comparative analysis shows that substrate binding initiates a large-scale domain closure in both species' DHQS and that the active site stereochemistry, of the catalytically competent closed-form enzyme thus produced, is also highly conserved. However, comparison of AnDHQS and SaDHQS open-form structures, and analysis of the putative dynamic processes by which the transition to the closed-form states are made, shows a far lower degree of similarity, indicating a significant structural divergence. As a result, both the nature of the propagation of conformational change and the mechanical systems involved in this propagation are quite different between the DHQSs from the two species. (C) 2004 Elsevier Ltd. All rights reserved.
Author(s): Nichols CE, Ren J, Leslie K, Dhaliwal B, Lockyer M, Charles I, Hawkins AR, Stammers DK
Publication type: Article
Publication status: Published
Journal: Journal of Molecular Biology
ISSN (print): 0022-2836
ISSN (electronic): 1089-8638
Publisher: Academic Press
Altmetrics provided by Altmetric