5K8H

The X-ray crystal structure of a parallel poly(rA) double helix generated by rA7 at acidic pH

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	SSRL BEAMLINE BL12-2
Synchrotron site	SSRL
Beamline	BL12-2
Temperature [K]	100
Detector technology	PIXEL
Collection date	2015-03-22
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.95530
Spacegroup name	P 42 21 2
Unit cell lengths	21.253, 21.253, 14.946
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	15.028 - 1.069
R-factor	0.1063
Rwork	0.106
R-free	0.10800
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	rA2 section of the 4JRD
Data reduction software	XDS
Data scaling software	Aimless
Phasing software	PHENIX
Refinement software	PHENIX ((1.10.1_2155: ???))

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	21.250	1.140
High resolution limit [Å]	1.069	1.069
Rmerge	0.127	1.059
Rpim	0.032	0.333
Number of reflections	1679
<I/σ(I)>	15	3.1
Completeness [%]	97.6	87.2
Redundancy	19.3	8.9
CC(1/2)	0.994	0.987

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	3.5	293.15	rA7 dissolved in water to 10 mM and was diluted 1/10 v/v in 0.75% PEG 1000. One uL of this was mixed with 1 uL of the following reservoir solution: (0.24 M ammonium sulfate and 0.06 M citric acid pH 3.5) to generate a hanging drop over 1 mL of this reservoir solution.