6N4J

Ti(III)citrate-reduced, nucleotide-free form of the nitrogenase Fe-protein from A. vinelandii

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1G5P

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	5.5	298	37% PEG 3350, 0.05 M NaCl, 0.1 M Bis/Tris pH 5.5, 5 mM Ti(III) citrate

Crystal Properties
Matthews coefficient	Solvent content
2.55	51.72

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 57.25	α = 90
b = 93.05	β = 98.5
c = 60.77	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	PIXEL	DECTRIS PILATUS 6M		2013-06-28	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL12-2	0.9801	SSRL	BL12-2

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Sym I (Observed)	Rrim I (All)	Rpim I (All)	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	1.95	60.102	90.7	0.059	0.064	0.026	11.2	5.4		41566

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	R-Sym I (Observed)	Rrim I (All)	Rpim I (All)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.95	2.06	92.4		0.446	0.446	0.495	0.211	1.5	5.2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	1G5P	1.95	44.68	39130	1987	89.69	0.2159	0.2141	0.249	RANDOM	48.932

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]
-1.71		2.74	-5.13		5.77

RMS Deviations
Key	Refinement Restraint Deviation
r_dihedral_angle_2_deg	34.125
r_dihedral_angle_4_deg	20.526
r_dihedral_angle_3_deg	15.766
r_dihedral_angle_1_deg	6.824
r_angle_refined_deg	2.268
r_angle_other_deg	1.622
r_chiral_restr	0.096
r_bond_refined_d	0.016
r_gen_planes_refined	0.007
r_bond_other_d	0.005

RMS Deviations
Key	Refinement Restraint Deviation
r_dihedral_angle_2_deg	34.125
r_dihedral_angle_4_deg	20.526
r_dihedral_angle_3_deg	15.766
r_dihedral_angle_1_deg	6.824
r_angle_refined_deg	2.268
r_angle_other_deg	1.622
r_chiral_restr	0.096
r_bond_refined_d	0.016
r_gen_planes_refined	0.007
r_bond_other_d	0.005
r_gen_planes_other	0.001

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4280
Nucleic Acid Atoms
Solvent Atoms	78
Heterogen Atoms	8

Software

Software
Software Name	Purpose
REFMAC	refinement
XDS	data reduction
SCALA	data scaling
PHASER	phasing
PDB_EXTRACT	data extraction

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.