2OKS

X-ray Structure of a DNA Repair Substrate Containing an Alkyl Interstrand Crosslink at 1.65 Resolution

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	ROTATING ANODE
Source details	RIGAKU
Temperature [K]	200
Detector technology	IMAGE PLATE
Collection date	2004-08-01
Detector	RIGAKU RAXIS IV
Spacegroup name	C 1 2 1
Unit cell lengths	31.870, 24.890, 34.350
Unit cell angles	90.00, 114.50, 90.00

Refinement procedure

Resolution	18.890 - 1.650
Rwork	0.182
R-free	0.20800
Structure solution method	FOURIER SYNTHESIS
Starting model (for MR)	1en8
RMSD bond length	0.012
RMSD bond angle	1.100
Data reduction software	DENZO
Data scaling software	SCALEPACK
Phasing software	CNS
Refinement software	CNS (1.1)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	40.000	1.710
High resolution limit [Å]	1.650	1.650
Number of reflections	2924
<I/σ(I)>	38.1	25.7
Completeness [%]	96.1	79.4
Redundancy	4.1	2.56

Crystallization Conditions

crystal ID	method	pH	temperature	details
1		8		The purified crosslinked DNA was dissolved in a buffer containing 22 mM ammonium acetate, 11 mM tris-hydroxymethyl-aminomethane (Tris)-HCl pH 8.0, and 11 mM calcium acetate. Crystals were grown using the sitting drop vapor diffusion method at 277K, in which 3 uL of a reservoir solution containing 27% 2-3 methyl-pentadiol, 115 mM calcium acetate, and 10 mM Tris-HCl pH 8.0 was added to an equal volume of DNA solution, and the mixture was equilibrated against 700 uL of the reservoir solution. Crystals first appeared after two weeks.

Crystallization Reagents

ID	crystal ID	solution ID	reagent name	concentration	details
1	1	1	2-3 methyl-pentadiol
2	1	1	calcium acetate
3	1	1	Tris-HCl
4	1	1	ammonium acetate
5	1	1	H2O
6	1	2	2-3 methyl-pentadiol
7	1	2	calcium acetate
8	1	2	Tris-HCl
9	1	2	H2O