An Unusual Cation-Binding Site and Distinct Domain-Domain Interactions Distinguish Class II Enolpyruvylshikimate-3-phosphate Synthases

Samuel H. Light, Sankar N. Krishna, George Minasov, Wayne F. Anderson*

*Corresponding author for this work

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

Enolpyruvylshikimate-3-phosphate synthase (EPSPS) catalyzes a critical step in the biosynthesis of a number of aromatic metabolites. An essential prokaryotic enzyme and the molecular target of the herbicide glyphosate, EPSPSs are the subject of both pharmaceutical and commercial interest. Two EPSPS classes that exhibit low sequence homology, differing substrate/glyphosate affinities, and distinct cation activation properties have previously been described. Here, we report structural studies of the monovalent cation-binding class II Coxiella burnetii EPSPS (cbEPSPS). Three cbEPSPS crystal structures reveal that the enzyme undergoes substantial conformational changes that alter the electrostatic potential of the active site. A complex with shikimate-3-phosphate, inorganic phosphate (Pi), and K+ reveals that ligand induced domain closure produces an unusual cation-binding site bordered on three sides by the N-terminal domain, C-terminal domain, and the product Pi. A crystal structure of the class I Vibrio cholerae EPSPS (vcEPSPS) clarifies the basis of differential class I and class II cation responsiveness, showing that in class I EPSPSs a lysine side chain occupies the would-be cation-binding site. Finally, we identify distinct patterns of sequence conservation at the domain-domain interface and propose that the two EPSPS classes have evolved to differently optimize domain opening-closing dynamics. (Figure Presented).

Original languageEnglish (US)
Pages (from-to)1239-1245
Number of pages7
JournalBiochemistry
Volume55
Issue number8
DOIs
StatePublished - Mar 1 2016

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'An Unusual Cation-Binding Site and Distinct Domain-Domain Interactions Distinguish Class II Enolpyruvylshikimate-3-phosphate Synthases'. Together they form a unique fingerprint.

  • Cite this