1CLI

X-RAY CRYSTAL STRUCTURE OF AMINOIMIDAZOLE RIBONUCLEOTIDE SYNTHETASE (PURM), FROM THE E. COLI PURINE BIOSYNTHETIC PATHWAY, AT 2.5 A RESOLUTION

Experimental procedure

Experimental method	MAD
Source type	SYNCHROTRON
Source details	CHESS BEAMLINE F2
Synchrotron site	CHESS
Beamline	F2
Temperature [K]	170
Detector technology	CCD
Collection date	1998-02
Detector	ADSC
Wavelength(s)	0.9792,0.9790,0.9638
Spacegroup name	P 21 21 21
Unit cell lengths	71.170, 211.680, 94.450
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	20.000 - 2.500
Rwork	0.192
R-free	0.26400
Structure solution method	MAD
RMSD bond length	0.009
RMSD bond angle	25.000 *
Data reduction software	MOSFLM
Data scaling software	CCP4 ((SCALA))
Phasing software	SnB
Refinement software	X-PLOR (3.8)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	20.000	2.640
High resolution limit [Å]	2.500	2.500
Rmerge	0.047 *	0.143 *
Number of reflections	44742
<I/σ(I)>	8.8	5.1
Completeness [%]	91.4	93
Redundancy	4.2	4.1

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	Vapor diffusion, hanging drop *	5.6		drop consists of equal volume of protein and reservoir solutions *

Crystallization Reagents in Literatures

ID	crystal ID	solution	reagent name	concentration (unit)	details
1	1	drop	protein	12 (mg/ml)
2	1	drop	Tris-HCl	15 (mM)
3	1	drop	dithiothreitol	10 (mM)
4	1	reservoir	ammonium sulfate	2.1-2.25 (M)
5	1	reservoir	isopropanol	3-6 (%(v/v))