4XPI

Fe protein independent substrate reduction by nitrogenase variants altered in intramolecular electron transfer

X-RAY DIFFRACTION

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Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	3U7Q

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	LIQUID DIFFUSION	8	298	30% PEG 4000, 100mM Tris-HCl pH 8.0, 170-190mM Sodium molybdate and 1mM Dithionite, LIQUID DIFFUSION, temperature 298.0K

Crystal Properties
Matthews coefficient	Solvent content
2.29	46.4

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 80.804	α = 90
b = 130.83	β = 111.14
c = 108.11	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	CCD	MARMOSAIC 325 mm CCD		2012-02-04	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL9-2	0.97	SSRL	BL9-2

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (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	1.97	35.8	96.39	2.5	3.5		141514

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 (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	3U7Q	1.97	35	134339	7087	96.39	0.21557	0.21303	0.22	0.26359	0.27	RANDOM	41.796

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]
3.66		0.5	-0.91		-2.39

RMS Deviations
Key	Refinement Restraint Deviation
r_dihedral_angle_2_deg	36.531
r_dihedral_angle_4_deg	21.525
r_dihedral_angle_3_deg	14.534
r_dihedral_angle_1_deg	6.738
r_angle_refined_deg	2.922
r_angle_other_deg	1.404
r_chiral_restr	0.273
r_bond_refined_d	0.02
r_gen_planes_refined	0.01
r_bond_other_d	0.001
r_gen_planes_other	0.001
r_nbd_refined
r_nbd_other
r_nbtor_refined
r_nbtor_other
r_xyhbond_nbd_refined
r_xyhbond_nbd_other
r_metal_ion_refined
r_metal_ion_other
r_symmetry_vdw_refined
r_symmetry_vdw_other
r_symmetry_hbond_refined
r_symmetry_hbond_other
r_symmetry_metal_ion_refined
r_symmetry_metal_ion_other
r_mcbond_it
r_mcbond_other
r_mcangle_it
r_mcangle_other
r_scbond_it
r_scbond_other
r_scangle_it
r_scangle_other
r_long_range_B_refined
r_long_range_B_other
r_rigid_bond_restr
r_sphericity_free
r_sphericity_bonded

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	15937
Nucleic Acid Atoms
Solvent Atoms	921
Heterogen Atoms	202

Software

Software
Software Name	Purpose
REFMAC	refinement
HKL-2000	data reduction
HKL-2000	data scaling
MOLREP	phasing