Structure of the Enterococcus faecalis EIIA(gnt) PTS component.
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).
Reinelt
Stefan
S
European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
Koch
Brigitte
B
Hothorn
Michael
M
Hengstenberg
Wolfgang
W
Welti
Stefan
S
Scheffzek
Klaus
K
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
D005942:Gluconates; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030691:gluconic acid