Mechanisms of allosteric activation and inhibition of the deoxyribonucleoside triphosphate triphosphohydrolase from Enterococcus faecalis

Ivan I. Vorontsov, Ying Wu, Maria Delucia, George Minasov, Jennifer Mehrens, Ludmilla Shuvalova, Wayne F. Anderson*, Jinwoo Ahn

*Corresponding author for this work

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

EF1143 from Enterococcus faecalis, a life-threatening pathogen that is resistant to common antibiotics, is a homo-tetrameric deoxyribonucleoside triphosphate (dNTP) triphosphohydrolase (dNTPase), converting dNTPs into the deoxyribonucleosides and triphosphate. The dNTPase activity of EF1143 is regulated by canonical dNTPs, which simultaneously act as substrates and activity modulators. Previous crystal structures of apo-EF1143 and the protein bound to both dGTP and dATP suggested allosteric regulation of its enzymatic activity by dGTP binding at four identical allosteric sites. However, whether and how other canonical dNTPsregulatetheenzyme activity was not defined.Here, wepresent the crystal structure of EF1143 in complex with dGTP and dTTP. The new structure reveals that the tetrameric EF1143 contains four additional secondary allosteric sites adjacent to the previously identified dGTP-binding primary regulatory sites. Structural and enzyme kinetic studies indicate that dGTP binding to the first allosteric site, with nanomolar affinity, is a prerequisite for substrate docking and hydrolysis. Then, the presence of a particular dNTP in the second site either enhances or inhibits the dNTPase activity of EF1143. Our results provide the first mechanistic insight into dNTP-mediated regulation of dNTPase activity.

Original languageEnglish (US)
Pages (from-to)2815-2824
Number of pages10
JournalJournal of Biological Chemistry
Volume289
Issue number5
DOIs
StatePublished - Jan 31 2014

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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