1DE0

MODULATING THE MIDPOINT POTENTIAL OF THE [4FE-4S] CLUSTER OF THE NITROGENASE FE PROTEIN

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	SMALL TUBES	8.5	277	PEG 4000, 0.1 M TRIS HCL, 0.2 M SODIUM ACETATE, pH 8.5, SMALL TUBES, temperature 277K

Crystal Properties
Matthews coefficient	Solvent content
2.55	51.83

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 56.54	α = 90
b = 91.05	β = 99.76
c = 63.35	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		1999-02-15	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU300

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	2.4	20	9.37	0.077		6	265157	24852		18.4	36.3

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)
	2.4	2.44	0.2		0.253		6

Refinement

Statistics
Diffraction ID	Structure Solution Method	Resolution (High)	Resolution (Low)	Number Reflections (All)	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		2.4	20	265157	22802	1152		0.221	0.221	0.281	5.0

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_bond_d	0.01
x_bond_d_na
x_bond_d_prot
x_angle_d
x_angle_d_na
x_angle_d_prot
x_angle_deg
x_angle_deg_na
x_angle_deg_prot
x_dihedral_angle_d
x_dihedral_angle_d_na
x_dihedral_angle_d_prot
x_improper_angle_d
x_improper_angle_d_na
x_improper_angle_d_prot
x_mcbond_it
x_mcangle_it
x_scbond_it
x_scangle_it

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4380
Nucleic Acid Atoms
Solvent Atoms	224
Heterogen Atoms	8

Software

Software
Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing