2W3M

HUMAN DIHYDROFOLATE REDUCTASE COMPLEXED WITH NADPH AND FOLATE

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	CHESS BEAMLINE A1
Synchrotron site	CHESS
Beamline	A1
Temperature [K]	100
Detector technology	CCD
Collection date	1996-06-28
Detector	ADSC QUANTUM-1
Spacegroup name	C 2 2 21
Unit cell lengths	88.552, 94.269, 96.681
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	10.700 - 1.600
R-factor	0.169
Rwork	0.167
R-free	0.20800
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1drf
RMSD bond length	0.013
RMSD bond angle	1.583
Data reduction software	MOSFLM
Data scaling software	SCALA
Phasing software	AMoRE
Refinement software	REFMAC (5.2.0019)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	10.700	1.690
High resolution limit [Å]	1.600	1.600
Rmerge	0.050	0.350
Number of reflections	52618
<I/σ(I)>	4.5	1.8
Completeness [%]	98.4	93.6
Redundancy	5.6	3.1

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	8.75	277	HUMAN DHFR/FOLATE COMPLEX WAS MIXED WITH NADPH (2 MM FINAL). CRYSTALS WERE GROWN BY HANGING DROP VAPOR DIFFUSION AT 277 K BY MIXING EQUAL VOLUMES OF PROTEIN/NADPH/FOLATE WITH RESERVOIR (24% PEG 4000, 200 MM LI2SO4, 100 MM TRIS.HCL, PH 8.75). TRUNCATED TRIANGULAR CRYSTALS APPEARED SLOWLY, IN ABOUT A MONTH. THE CRYSTAL WAS CRYOPROTECTED WITH 15% GLYCEROL AND FLASH-COOLED IN LIQUID N2.