DNA binding activity of Anabaena sensory rhodopsin transducer probed by fluorescence correlation spectroscopy

Figures & data

Table 1. DNA sequences.

Name	Sequence
R2^*	5′-GCAATCGACCTTATAAAAAG-3′
R3**	5′-ATGACCTTTAGGAGGAAAGA-3′
Rand20	5′-TACCTCGGAGGCAATAGCTT-3′
Amp^***	5′-GCGGTTAGCTCCTTCGGTCC-3′
PolyA	5′-AAAAAAAAAAAAAAAAAAAA-3′

^* R2 sequence was selected from the pec promoter region (−55 to −36).

^** R3 sequence was selected from the pec promoter region (−30 to −11).

^*** Amp sequence was selected from the ampicillin gene (+427 to +446).

Fig. 1. Normalized correlation functions of fluorescence-labeled DNA (R3).

Notes: (a) Correlation functions measured at different concentrations of ASRT (symbols) with the best fits to the data (solid lines). Inset: magnification of the middle region of the correlation functions. (b) Correlation functions measured with (red) and without (black) 100 μM BSA. Inset: magnification of the middle region of the correlation functions.

Fig. 2. The fraction bound obtained from the five different sequences listed in Table 1.

Notes: Filled box: Amp (sequence adapted from ampicillin gene), open circle: R3 (from pec promoter), open triangle: R2 (from pec promoter), filled diamond: PolyA (A tract), and cross: Rand20 (random sequence). Solid lines are the best fits to the Hill equation. Error bars are standard deviations from three independent sets of ASRT concentration-dependent FCS measurements.

Fig. 3. The dissociation constant, K_D, of ASRT on different DNA sequences.

Note: Error bars are standard errors from three independent sets of ASRT concentration-dependent FCS measurements.