5EYQ

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

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	ROTATING ANODE
Source details	RIGAKU FR-X
Temperature [K]	150
Detector technology	PIXEL
Collection date	2015-04-17
Detector	DECTRIS PILATUS 200K
Wavelength(s)	1.54
Spacegroup name	P n n a
Unit cell lengths	28.905, 68.454, 34.211
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	34.230 - 2.300
R-factor	0.27591
Rwork	0.272
R-free	0.35745
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1bna
RMSD bond length	0.011
RMSD bond angle	1.668
Data reduction software	XDS
Data scaling software	XDS
Phasing software	PHASER
Refinement software	REFMAC (5.8.0073)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	34.230	2.380
High resolution limit [Å]	2.300	2.300
Rmerge	0.045	0.175
Number of reflections	2825
<I/σ(I)>	8.87	1.34
Completeness [%]	96.6	78.57
Redundancy	1.8	1.6

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	7	293	Racemic DNA solution*, sodium cacodylate, magnesium chloride, sodium chloride, spermine tetrahydrochloride, MPD *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 L-DNA solution (strands 1,2) and D-DNA solution (strands 3,4) were prepared first with denaturation followed by slow annealing process to ensure proper folding of the duplex formed between the non-self complementary strands. After annealing, the enantiopure solutions were mixed in equimolar ratio and this racemic mixture was used for crystallization.