3NPQ

Structure of the S-adenosylhomocysteine riboswitch at 2.18 A

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	NSLS BEAMLINE X25
Synchrotron site	NSLS
Beamline	X25
Temperature [K]	100
Detector technology	CCD
Collection date	2009-10-02
Detector	ADSC QUANTUM 315
Wavelength(s)	0.9795
Spacegroup name	C 1 2 1
Unit cell lengths	93.793, 103.241, 69.583
Unit cell angles	90.00, 97.90, 90.00

Refinement procedure

Resolution	23.014 - 2.181
R-factor	0.2358
Rwork	0.235
R-free	0.24540
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	3npn
RMSD bond length	0.001
RMSD bond angle	0.536
Data reduction software	MOSFLM
Data scaling software	SCALA (3.3.15)
Phasing software	PHASER
Refinement software	PHENIX (1.4_87)

Data quality characteristics

	Overall	Inner shell	Outer shell
Low resolution limit [Å]	23.014	23.014	2.050
High resolution limit [Å]	1.950	6.160	1.950
Rmerge		0.052	1.005
Rmeas		0.057	1.157
Rpim		0.022	0.566
Total number of observations		9346	13006
Number of reflections	41336
<I/σ(I)>		31.1	1.4
Completeness [%]	86.4	93.1	47
Redundancy	6.2	6.4	4

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	hanging drop	7	293	2.25 mM Spermine, 9 mM magnesium chloride, 0.9 mM spermidine, 2.5 mM Cobalt(III)hexammine chloride, 0.05 M sodium cacodylate pH 7.0, 5% (v/v) PEG 400, hanging drop, temperature 293K