TABLE 1.

Equilibrium constants and in vivo concentrations for the PFL system

In vivo concentrations for the PFL family were calculated using previously determined polypeptide measurements and combined with cell volume measurements of 2.9 ± 1.2 fl for E. coli cells grown in minimal media supplemented with glucose under anaerobic conditions (5, 36). In vivo concentrations under anaerobic conditions were as follows: [PFL-AE] = 1.1 μm, [PFL] = 20 μm, [Fld] = 2.9 μm, [FNR] = 2.3 μm, [PFOR] = 648 nm. Equilibrium constants were taken from previously published data (47). Error calculations could not be performed because error information was not available for polypeptide measurements (5, 48).

Sample	KD	[Bound in vivo]	% Bound in vivo
	μm	nm
FNR: Fld	3.7 ± 1.6 μm	826	36
PFL-AE:PFL	1.1 ± 0.2 μm	1070	97
PFL-AE:Fld	23.3 ± 3.8 μm	117	11
PFL-AE:AdoMet	7.6 ± 1.9 μm	952	86
PFL-AE·PFL:AdoMet	5.7 ± 1.7 μm	985	90