title: Structure of the Enterococcus faecalis EIIA(gnt) PTS component.
abstract: 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).
authors.affiliation: European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Reinelt
authors.forename: Brigitte
authors.initials: B
authors.lastname: Koch
authors.forename: Michael
authors.initials: M
authors.lastname: Hothorn
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hengstenberg
authors.forename: Stefan
authors.initials: S
authors.lastname: Welti
authors.forename: Klaus
authors.initials: K
authors.lastname: Scheffzek
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D013293:Enterococcus faecalis / Q000201:enzymology*; D005942:Gluconates / Q000378:metabolism; D008969:Molecular Sequence Data; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D005942:Gluconates; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030691:gluconic acid