1K4T

HUMAN DNA TOPOISOMERASE I (70 KDA) IN COMPLEX WITH THE POISON TOPOTECAN AND COVALENT COMPLEX WITH A 22 BASE PAIR DNA DUPLEX

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
Spacegroup name	P 1 21 1
Unit cell lengths	57.093, 116.260, 75.217
Unit cell angles	90.00, 94.16, 90.00

Refinement procedure

Resolution	19.890 - 2.100
Rwork	0.229
R-free	0.27100 *
Structure solution method	MOLECULAR REPLACEMENT
RMSD bond length	0.007 *
RMSD bond angle	1.170 *
Data reduction software	DENZO
Data scaling software	SCALEPACK
Phasing software	CNX
Refinement software	CNX

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	20.000	2.150
High resolution limit [Å]	2.100	2.100
Rmerge	0.062 *
Number of reflections	46866
<I/σ(I)>	18.6	1.71
Completeness [%]	81.1 *	32.8

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP	6.5	16 *	PEG 8000, Ammonium Sulfate, MES, pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 289K

Crystallization Reagents

ID	crystal ID	solution ID	reagent name	concentration	details
1	1	1	PEG 8000
2	1	1	Ammonium Sulfate
3	1	1	MES

Crystallization Reagents in Literatures

ID	crystal ID	solution	reagent name	concentration (unit)	details
1	1	reservoir	PEG8000	10 (%(w/v))
2	1	reservoir	lithium sulfate	200 (mM)
3	1	reservoir		100 (mM)	pH6.5
4	1	drop	suicide duplex substrate	0.05 (mM)
5	1	drop	topotecan	10 (mM)