Activity of the Enterococcus faecalis EIIA(gnt) PTS component and its strong interaction with EIIBgnt

作者：Brockmeier Achim; Skopnik Manuel; Koch Brigitte; Herrmann Christian; Hengstenberg Wolfgang; Welti Stefan; Scheffzek Klaus^*

来源：Biochemical and Biophysical Research Communications, 2009, 388(4): 630-636.

DOI：10.1016/j.bbrc.2009.08.100

• Enterococcus faecalis
• EIIA
• Phosphotransferase system
• Mannose
• Histidine
• EIIB
• Association constant
• Complex
• Sugar
• Import

Eubacteria can import and simultaneously phosphorylate a range of different carbohydrates by means of sugar specific phosphoenolpyruvate (PEP) dependent sugar phosphotransferase systems (PTSs). Here, we report the biochemical characterization of the gluconate specific PTS component EIIA(gnt) from Enterococcus faecalis and its unexpectedly strong complex with EIIBgnt. We analyze the activity of the complex regarding phosphoryl transfer using kinetic measurements and demonstrate by mutagenesis that His-9 of EIIA(gnt) is essential for this process and represents most likely the phosphoryl group carrier of EIIA(gnt). With a combination of isothermal titration calorimetry (ITC), analytical ultracentrifugation (AUC), native gel electrophoresis and chemical crosslinking experiments we show that EIIA(gnt) and EIIBgnt form a strong 2: 2 heterotetrameric complex, which seems to be destabilized upon phosphorylation of EIIBgnt.

• 出版日期2009-10-30