5EZF

Racemic crystal structures of Pribnow box consensus promoter sequence (Pbca)

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	SOLEIL BEAMLINE PROXIMA 1
Synchrotron site	SOLEIL
Beamline	PROXIMA 1
Temperature [K]	100
Detector technology	PIXEL
Collection date	2015-06-11
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.9785
Spacegroup name	P b c a
Unit cell lengths	41.736, 39.329, 65.713
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	32.856 - 1.650
R-factor	0.2973
Rwork	0.296
R-free	0.31670
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1fq2
RMSD bond length	0.007
RMSD bond angle	1.626
Data reduction software	XDS
Data scaling software	XDS
Phasing software	PHASER
Refinement software	PHENIX (1.8.2_1309)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	32.860	1.790
High resolution limit [Å]	1.650	1.650
Rmerge	0.019	0.268
Number of reflections	12549
<I/σ(I)>	16.92	2.75
Completeness [%]	99.9	99.76
Redundancy	1.9	1.9

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	7.5	293	Racemic DNA mixture*, HEPES, calcium chloride, PEG400 * For crystallization, we used four strands 1) d(CGCTATAATGCG) with L-sugars 2) d(CGCATTATAGCG) with L-sugars and 3) d(CGCTATAATGCG) with D-sugars 4) d(CGCATTATAGCG) with D-sugars Enantio-pure DNA solutions were prepared first by de-naturation followed by slow cooling down process to ensure proper folding of the hetero-duplex formed between the non-self complementary strands. After slow-annealing, the enantiopure solutions were mixed in equimolar ratio and this racemic DNA mixture was used for crystallization.