1CP2

NITROGENASE IRON PROTEIN FROM CLOSTRIDIUM PASTEURIANUM

X-RAY DIFFRACTION

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Starting Model(s)

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

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	liquid - liquid diffusion	7.5		PROTEIN WAS CRYSTALLIZED BY LIQUID-LIQUID DIFFUSION METHOD. PRECIPITANT CONTAINED 5-15% GLYCEROL, 18.75-22.5% PEG 4000, 230-270 MM CACL2, AND 50 MM HEPES PH 7.5. PROTEIN WAS STORED BEFORE CRYSTALLIZATION IN 20% GLYCEROL, 50 MM HEPES, PH 7.5, AND 2 MM NA2S2O4., liquid - liquid diffusion

Crystal Properties
Matthews coefficient	Solvent content
2.18	43

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 67.6	α = 90
b = 75.87	β = 114.17
c = 53.55	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	IMAGE PLATE	RIGAKU RAXIS IIC		1993-11-06	M

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

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	1.93	15.63	98.8	0.0725	5.8	6.8		36808			34.5

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	1.93	2	91

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	PDB ENTRY 1NIP	1.93	5	31231	3083	98.8	0.209	0.209	0.297	RANDOM	36.3

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_dihedral_angle_d	24.1
x_angle_deg	2
x_improper_angle_d	1.89
x_bond_d	0.018
x_bond_d_na
x_bond_d_prot
x_angle_d
x_angle_d_na
x_angle_d_prot
x_angle_deg_na
x_angle_deg_prot
x_dihedral_angle_d_na
x_dihedral_angle_d_prot
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	3940
Nucleic Acid Atoms
Solvent Atoms	114
Heterogen Atoms	8

Software

Software
Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
R-AXIS	data reduction
REFSTAT	data scaling
X-PLOR	phasing