1IA3

Candida albicans dihydrofolate reductase complex in which the dihydronicotinamide moiety of dihydro-nicotinamide-adenine-dinucleotide phosphate (NADPH) is displaced by 5-[(4-TERT-BUTYLPHENYL)SULFANYL]-2,4-QUINAZOLINEDIAMINE (GW995)

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1AI9	CANDIDA ALBICANS DHFR (PDB ENTRY 1AI9)

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6.5	277	DIHYDRO-NICOTINAMIDE-ADENINE- DINUCLEOTIDE PHOSPHATE (NADPH),5-[(4-TERT-BUTYLPHENYL) SULFANYL]-2,4-QUINAZOLINEDIAMINE (GW995), PEG-3350, POTASSIUM 4-MORPHILINEERHANESULFONIC ACID, DITHIOTHREITOL A THREE-FOLD EXCESS OF GW995 AND THREE-FOLD EXCESS OF NADPH WAS ADDED TO THE C. ALBICANS DHFR SOLUTION AND LET STAND 277K OVERNIGHT. 17-20 MG/ML C. ALBICANS DHFR IN 50 UM GW995, 50 UM NADPH, 20 MM KMES, 1 MM DTT, PH 6.5 WAS MIXED WITH AN EQUAL PART OF 26 - 34% PEG-3350, THE RESERVOIR SOLUTION. , VAPOR DIFFUSION, HANGING DROP

Crystal Properties
Matthews coefficient	Solvent content
2.27	43

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 76.91	α = 90
b = 67.28	β = 93.07
c = 38.49	γ = 90

Symmetry
Space Group	P 1 21 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	293	AREA DETECTOR	XENTRONICS	Huber graphite monochromator	1988-08-30	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	ELLIOTT GX-21

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	R Sym I (Observed)	Net I Over Average Sigma (I)	Redundancy	Number Reflections (All)	Number Reflections (Observed)	Observed Criterion Sigma (F)	Observed Criterion Sigma (I)	B (Isotropic) From Wilson Plot
1	1.75	25	90.1	0.0549	0.0549	16.18	3.24	116944	36058		-3	36.3

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	1.75	1.85	60.4		0.2694	0.2694	2.23	1.11	4005

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (All)	R-Factor (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	DIRECT REPLACEMENT	CANDIDA ALBICANS DHFR (PDB ENTRY 1AI9)	1.78	10	2	36058	32308		84.6	0.16	0.16	0.16

Temperature Factor Modeling
Anisotropic B[1][1]	Anisotropic B[1][2]	Anisotropic B[1][3]	Anisotropic B[2][2]	Anisotropic B[2][3]	Anisotropic B[3][3]

RMS Deviations
Key	Refinement Restraint Deviation
p_transverse_tor	32.6
p_staggered_tor	14.9
p_scangle_it	3.826
p_planar_tor	3.8
p_scbond_it	2.401
p_mcangle_it	1.462
p_mcbond_it	0.847
p_chiral_restr	0.243
p_singtor_nbd	0.167
p_multtor_nbd	0.148

RMS Deviations
Key	Refinement Restraint Deviation
p_transverse_tor	32.6
p_staggered_tor	14.9
p_scangle_it	3.826
p_planar_tor	3.8
p_scbond_it	2.401
p_mcangle_it	1.462
p_mcbond_it	0.847
p_chiral_restr	0.243
p_singtor_nbd	0.167
p_multtor_nbd	0.148
p_xyhbond_nbd	0.136
p_planar_d	0.04
p_angle_d	0.034
p_bond_d	0.021
p_plane_restr	0.021
p_hb_or_metal_coord
p_xhyhbond_nbd
p_special_tor

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3181
Nucleic Acid Atoms
Solvent Atoms	350
Heterogen Atoms	140

Software

Software
Software Name	Purpose
X-GEN	data reduction
FRODO	model building
PROFFT	refinement
X-GEN	data scaling

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.