1KGK

Direct Observation of a Cytosine Analog that Forms Five Hydrogen Bonds to Guanosine; Guanyl G-Clamp

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	APS BEAMLINE 5ID-B
Synchrotron site	APS
Beamline	5ID-B
Temperature [K]	120
Detector technology	CCD
Collection date	2000-04-29
Detector	MARRESEARCH
Wavelength(s)	0.978
Spacegroup name	P 21 21 21
Unit cell lengths	24.520, 43.020, 46.680
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	10.000 - 1.000
Structure solution method	MOLECULAR REPLACEMENT
RMSD bond length	0.015
RMSD bond angle	0.021
Data reduction software	DENZO
Data scaling software	SCALEPACK
Phasing software	AMoRE
Refinement software	SHELXL-97

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	20.000 *	1.100
High resolution limit [Å]	1.000	1.000
Rmerge	0.047
Number of reflections	27320
Completeness [%]	99.6	99.6

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	Vapor diffusion, hanging drop *	6	298	1.2 mM DNA, 5% MPD, 20 mM Sodium Cacodylate, 40 mM sodium chloride, 6 mM potassium chloride, 10 mM magnesium chloride; equilibrated against 35% MPD, pH 6.0, Hanging Drop, temperature 298K

Crystallization Reagents

ID	crystal ID	solution ID	reagent name	concentration	details
1	1	1	MPD
10	1	2	MPD
11	1	2	Sodium Cacodylate
2	1	1	Sodium Cacodylate
3	1	1	NaCl
4	1	1	KCl
5	1	1	MgCl2
6	1	1	MPD
7	1	2	NaCl
8	1	2	KCl
9	1	2	MgCl2

Crystallization Reagents in Literatures

ID	crystal ID	solution	reagent name	concentration (unit)	details
1	1	drop	DNA	1.2 (mM)
2	1	drop	MPD	5 (%)
3	1	drop	sodium cacodylate	20 (mM)	pH6.0
4	1	drop	spermine 4HCl	6 (mM)
5	1	drop		40 (mM)
6	1	drop		6 (mM)
7	1	drop		10 (mM)
8	1	reservoir	MPD	35 (%(v/v))