||Bacteria Escherichia coli
||Sourjik V, Berg HC. Binding of the Escherichia coli response regulator CheY to its target measured in vivo by fluorescence resonance energy transfer. Proc Natl Acad Sci U S A. 2002 Oct 1 99(20):12669-74. abstract & p.12673 left column 2nd paragraphPubMed ID12232047
||P.12669 left column bottom paragraph: "To learn more about the binding of CheY∼P to FliM and about the kinetics of the chemotactic response, [investigators] extended [their] recent analysis of phosphorylation-dependent interactions of CheY with CheZ (ref 9) and measured fluorescence resonance energy transfer (FRET) between cyan fluorescent protein (CFP) fused to the N terminus of FliM (CFP-FliM) and yellow fluorescent protein (YFP) fused to the C terminus of CheY (CheY-YFP). The FRET technique relies on the distance-dependent transfer of energy from an excited donor fluorophore (CFP) to an acceptor fluorophore (YFP) and allows one to monitor changes in protein interactions in real time in vivo (refs 10, 11)."
||Abstract: "Following sudden addition of repellent, FliM occupancy increased with a rate constant of about 20 s(-1)." p.12673 left column 2nd paragraph: "Stimulation of wild-type cells by flash photolysis of a caged proton, a repellent, Fig. 4C, revealed no measurable delay (<20 ms). The maximum FliM occupancy was reached within 70–100 ms. This is in a good agreement with the value of ≈50 ms obtained for free-swimming cells (ref 6). From the time required to reach ≈65% [1 − (1/e)] of the maximal repellent response (≈45 ms), the first-order rate constant of the repellent response was estimated as ≈22 s^−1."