3Q50

Structural analysis of a class I PreQ1 riboswitch aptamer in the metabolite-bound state

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	CHESS BEAMLINE A1
Synchrotron site	CHESS
Beamline	A1
Temperature [K]	100
Detector technology	CCD
Collection date	2009-11-09
Detector	ADSC QUANTUM 210
Wavelength(s)	0.9769
Spacegroup name	P 63 2 2
Unit cell lengths	110.782, 110.782, 59.605
Unit cell angles	90.00, 90.00, 120.00

Refinement procedure

Resolution	22.010 - 2.750
R-factor	0.2144
Rwork	0.210
R-free	0.25220
Structure solution method	FOURIER SYNTHESIS
Starting model (for MR)	3gca
RMSD bond length	0.007
RMSD bond angle	1.689
Data reduction software	HKL-2000
Data scaling software	SCALEPACK
Phasing software	PHENIX (1.6_289)
Refinement software	PHENIX (1.6_289)

Data quality characteristics

	Overall	Inner shell	Outer shell
Low resolution limit [Å]	25.000	25.000	2.800
High resolution limit [Å]	2.725	7.400	2.750
Rmerge	0.077	0.041	0.586
Number of reflections	6041
<I/σ(I)>	16.4
Completeness [%]	98.7	91.4	94.8
Redundancy	6.5	5.8	5.1

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	5.6	293	1.8 M Li2SO4, 0.05 M MES pH 5.6, and 0.01 M MgCl2(H20)6, vapor diffusion, hanging drop, temperature 293K