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Spatial and temporal organization of the E. coli PTS components
Author(s) -
Lopian Livnat,
Elisha Yair,
NussbaumShochat Anat,
AmsterChoder Orna
Publication year - 2010
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2010.240
Subject(s) - pep group translocation , permease , operon , biology , phosphorylation , subcellular localization , biochemistry , cytoplasm , microbiology and biotechnology , escherichia coli , signal transduction , transcription (linguistics) , inner membrane , bacteria , gene , membrane , genetics , linguistics , philosophy
The phosphotransferase system (PTS) controls preferential use of sugars in bacteria. It comprises of two general proteins, enzyme I (EI) and HPr, and various sugar‐specific permeases. Using fluorescence microscopy, we show here that EI and HPr localize near the Escherichia coli cell poles. Polar localization of each protein occurs independently, but HPr is released from the poles in an EI‐ and sugar‐dependent manner. Conversely, the β‐glucoside‐specific permease, BglF, localizes to the cell membrane. EI, HPr and BglF control the β‐glucoside utilization ( bgl ) operon by modulating the activity of the BglG transcription factor; BglF inactivates BglG by membrane sequestration and phosphorylation, whereas EI and HPr activate it by an unknown mechanism in response to β‐glucosides availability. Using biochemical, genetic and imaging methodologies, we show that EI and HPr interact with BglG and affect its subcellular localization in a phosphorylation‐independent manner. Upon sugar stimulation, BglG migrates from the cell periphery to the cytoplasm through the poles. Hence, the PTS components appear to control bgl operon expression by ushering BglG between the cellular compartments. Our results reinforce the notion that signal transduction in bacteria involves dynamic localization of proteins.