3QSF

The first crystal structure of a human telomeric G-quadruplex DNA bound to a metal-containing ligand (a nickel complex)

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	DIAMOND BEAMLINE I03
Synchrotron site	Diamond
Beamline	I03
Temperature [K]	105
Detector technology	CCD
Collection date	2010-06-28
Detector	ADSC QUANTUM 315r
Wavelength(s)	1.48660
Spacegroup name	C 2 2 2
Unit cell lengths	44.020, 54.909, 33.691
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	15.000 - 2.400
R-factor	0.2404
Rwork	0.237
R-free	0.32030
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	3qsc
RMSD bond length	0.014
RMSD bond angle	1.608
Data reduction software	XDS
Data scaling software	SCALA (3.3.16)
Phasing software	PHASER (2.1.4)
Refinement software	REFMAC

Data quality characteristics

	Overall	Inner shell	Outer shell
Low resolution limit [Å]	22.010	22.010	2.430
High resolution limit [Å]	2.308	7.290	2.310
Rmerge		0.043	0.153
Total number of observations		183	658
Number of reflections	1888
<I/σ(I)>	15.1	14.8	4.6
Completeness [%]	97.4	80.5	89.8
Redundancy	3.5	3.1	2.7

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	7	293.15	Initial conditions in the 3 ul drop were: 1.25mM quadruplex DNA, 1.25mM ligand, 0.83% PEG (w/v) 10 000, 16.7mM potassium chloride, 16.7mM sodium chloride, 16.7mM lithium sulphate and 20 mM potassium cacodylate buffer at pH 7.0. This was equilibrated against a reservoir well solution of 50% (w/v) PEG 10000 , VAPOR DIFFUSION, HANGING DROP, temperature 293.15K