Oligomeric sensor kinase DcuS in the membrane of Escherichia coli and in proteoliposomes: chemical cross-linking and FRET spectroscopy.

ABSTRACT: DcuS is the membrane-integral sensor histidine kinase of the DcuSR two-component system in Escherichia coli that responds to extracellular C(4)-dicarboxylates. The oligomeric state of full-length DcuS was investigated in vitro and in living cells by chemical cross-linking and by fluorescence resonance energy transfer (FRET) spectroscopy. The FRET results were quantified by an improved method using background-free spectra of living cells for determining FRET efficiency (E) and donor fraction {f(D) = (donor)/[(donor) + (acceptor)]}. Functional fusions of cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) variants of green fluorescent protein to DcuS were used for in vivo FRET measurements. Based on noninteracting membrane proteins and perfectly interacting proteins (a CFP-YF

SUBMITTER: Scheu PD 

PROVIDER: S-EPMC2897680 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature