Structure of the Enterococcus faecalis EIIA(gnt) PTS component

Biochem Biophys Res Commun. 2009 Oct 30;388(4):626-9. doi: 10.1016/j.bbrc.2009.08.054. Epub 2009 Aug 13.


In Eubacteria, the utilization of a number of extracellular carbohydrates is mediated by sugar specific phosphoenolepyruvate (PEP) dependent sugar phosphotransferase systems (PTSs), which simultaneously import und phosphorylate their target sugars. Here, we report the crystal structure of the EIIA(gnt) component of the so far little investigated Enterococcus faecalis gluconate specific PTS. The crystal structure shows a tightly interacting dimer of EIIA(gnt) which is structurally similar to the related EIIA(man) from Escherichia coli. Homology modeling of E. faecalis HPr, EIIB(man) and their complexes with EIIA(man) suggests that despite moderate sequence identity between EIIA(man) and EIIA(gnt), the active sites closely match the situation observed in the E. coli system with His-9 of EIIA(gnt) being the likely phosphoryl group carrier. We therefore propose that the phosphoryl transfer reactions involving EIIA(gnt) proceed according to a mechanism analog to the one described for E. coli EIIA(man).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Crystallography, X-Ray
  • Enterococcus faecalis / enzymology*
  • Gluconates / metabolism
  • Molecular Sequence Data
  • Phosphoenolpyruvate Sugar Phosphotransferase System / chemistry*
  • Protein Conformation


  • Gluconates
  • Phosphoenolpyruvate Sugar Phosphotransferase System
  • gluconic acid