3EGZ

Crystal structure of an in vitro evolved tetracycline aptamer and artificial riboswitch

Experimental procedure

Experimental method	MAD
Source type	SYNCHROTRON
Source details	ALS BEAMLINE 5.0.2
Synchrotron site	ALS
Beamline	5.0.2
Temperature [K]	100
Detector technology	CCD
Collection date	2008-02-14
Detector	ADSC QUANTUM 315
Wavelength(s)	0.9570,0.9797,0.9795
Spacegroup name	P 4 21 2
Unit cell lengths	120.835, 120.835, 55.279
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	29.310 - 2.200
R-factor	0.217
Rwork	0.212
R-free	0.26000
Structure solution method	MAD
RMSD bond length	0.013
RMSD bond angle	1.987
Data reduction software	DENZO
Data scaling software	SCALEPACK
Phasing software	SOLVE
Refinement software	REFMAC (5.4.0067)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	29.310	2.280
High resolution limit [Å]	2.200	2.200
Rmerge	0.008	0.532
Number of reflections	21415
<I/σ(I)>	37.6	3.8
Completeness [%]	99.1	99.9
Redundancy	9.5	9.8

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP	7	296	0.3 mM RNA, 0.33 mM selenomethionine labeled U1A-RBD double mutant, 0.5 mM chlorotetracycline, 50 mM Tris pH 7.5, 5 mM MgCl2, 0.25 mM spermine; 1uL macromolecular complex:1 uL reservoir; 50 mM HEPES-KOH pH 7.0, 20 mM MGCl2, 12.5-15% PEG 8000; cryo 30% glycerol, 50 mM HEPES-KOH pH 7.0, 20 mM MGCl2, 15% PEG 8000, 0.5 mM spermine, 0.5 mM chlorotetracycline, VAPOR DIFFUSION, SITTING DROP, temperature 296K

Crystallization Reagents

ID	crystal ID	solution ID	reagent name	concentration	details
1	1	1	MgCl2
2	1	1	spermine
3	1	1	HEPES-KOH
4	1	1	PEG 8000
5	1	1	glycerol
6	1	2	MgCl2
7	1	2	PEG 8000
8	1	2	HEPES-KOH