3NVT : 1.95 Angstrom crystal structure of a bifunctional 3-deoxy-7-phosphoheptulonate synthase/chorismate mutase (aroA) from Listeria monocytogenes EGD-e



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2010-07-28
Deposition Date:2010-07-08
Revision Date:2011-07-13#2012-04-25#2012-05-30#2017-11-08
Molecular Weight:85183.36
Macromolecule Type:Protein
Residue Count:770
Atom Site Count:5342

3-Deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS) catalyzes the first step in the biosynthesis of a number of aromatic metabolites. Likely because this reaction is situated at a pivotal biosynthetic gateway, several DAHPS classes distinguished by distinct mechanisms of allosteric regulation have independently evolved. One class of DAHPSs contains a regulatory domain with sequence homology to chorismate mutase-an enzyme further downstream of DAHPS that catalyzes the first committed step in tyrosine/phenylalanine biosynthesis-and is inhibited by chorismate mutase substrate (chorismate) and product (prephenate). Described in this work, structures of the Listeria monocytogenes chorismate/prephenate regulated DAHPS in complex with Mn(2+) and Mn(2+) + phosphoenolpyruvate reveal an unusual quaternary architecture: DAHPS domains assemble as a tetramer, from either side of which chorismate mutase-like (CML) regulatory domains asymmetrically emerge to form a pair of dimers. This domain organization suggests that chorismate/prephenate binding promotes a stable interaction between the discrete regulatory and catalytic domains and supports a mechanism of allosteric inhibition similar to tyrosine/phenylalanine control of a related DAHPS class. We argue that the structural similarity of chorismate mutase enzyme and CML regulatory domain provides a unique opportunity for the design of a multitarget antibacterial.
Date made available2010

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