1G1M

ALL-FERROUS NITROGENASE IRON PROTEIN FROM AZOTOBACTER VINELANDII

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1		8	295	26-29% PEG 4000, 700-900 mM NaCl, 100 mM Tris (pH 8.0), 20% glycerol, capillary microbatch method at 295 K

Crystal Properties
Matthews coefficient	Solvent content
2.62	53.14

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 57	α = 90
b = 93.3	β = 98.9
c = 62.8	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	113.15	IMAGE PLATE	MARRESEARCH		1999-12-21	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL7-1		SSRL	BL7-1

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	2.25	20	93.2	0.054	21.3			28724

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)
	2.25	2.39	87		0.319

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	2.25	18	28765	1480		0.238	0.288	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
c_dihedral_angle_d	24
c_angle_deg	1.7
c_improper_angle_d	0.95
c_bond_d	0.012

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4357
Nucleic Acid Atoms
Solvent Atoms	348
Heterogen Atoms	8

Software

Software
Software Name	Purpose
SHARP	phasing
CNS	refinement
MAR345	data collection
SCALEPACK	data scaling

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.