1FP4

CRYSTAL STRUCTURE OF THE ALPHA-H195Q MUTANT OF NITROGENASE

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	microcapillary batch diffusion	8	298	PEG 4000, TRIS pH 8.0, sodium molybdate, microcapillary batch diffusion, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.28	45.95

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 107.2	α = 90
b = 130.2	β = 111.2
c = 80.4	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	100	IMAGE PLATE	RIGAKU RAXIS IIC		1999-10-13	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU200

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge 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	2.5	20	93	0.082	7.9	6.4	63058	59345	1	1

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	2.5	20	70.9		0.082		6.4

Refinement

Statistics
Diffraction ID	Structure Solution Method	Resolution (High)	Resolution (Low)	Cut-off Sigma (I)	Cut-off Sigma (F)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION		2.5	20	1	1	63058	59345			0.184	0.24	random

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
x_angle_deg	2.53
x_bond_d	0.01

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	15768
Nucleic Acid Atoms
Solvent Atoms	433
Heterogen Atoms	94

Software

Software
Software Name	Purpose
SCALEPACK	data scaling
AMoRE	phasing
X-PLOR	refinement

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.