2C8V

Insights into the role of nucleotide-dependent conformational change in nitrogenase catalysis: Structural characterization of the nitrogenase Fe protein Leu127 deletion variant with bound MgATP

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1		8		24% POLY(ETHYLENE GLYCOL), MW 4000, 0.16 M MGCL2, TRISHYDROCHLORIC ACID, PH 8.5, 20% GLYCEROL, AND 1MM SODIUM DITHIONITE

Crystal Properties
Matthews coefficient	Solvent content
2.32	50.01

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 70.9	α = 90
b = 133.3	β = 90
c = 61.5	γ = 90

Symmetry
Space Group	C 2 2 21

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	93	CCD	MARRESEARCH	FLAT MIRRORS	2002-12-20	M	SINGLE WAVELENGTH

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

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	2.5	40	97.8	0.086	4.1	4		20818		1.5

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)
1	2.5		99.9		0.079	5.1	4.2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	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	OTHER	THROUGHOUT	2.5	8	2.5	22950		99.9	0.2381	0.2381	0.2793	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
x_angle_deg	2.52
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_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	2050
Nucleic Acid Atoms
Solvent Atoms	99
Heterogen Atoms	36

Software

Software
Software Name	Purpose
X-PLOR	refinement
Blu-Ice	data reduction
DENZO	data reduction
MOSFLM	data scaling
SCALEPACK	data scaling
SCALA	data scaling
X-PLOR	phasing