6N4J

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

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	SSRL BEAMLINE BL12-2
Synchrotron site	SSRL
Beamline	BL12-2
Temperature [K]	100
Detector technology	PIXEL
Collection date	2013-06-28
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.9801
Spacegroup name	P 1 21 1
Unit cell lengths	57.250, 93.050, 60.770
Unit cell angles	90.00, 98.50, 90.00

Refinement procedure

Resolution	44.680 - 1.950
R-factor	0.2159
Rwork	0.214
R-free	0.24900
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1g5p
RMSD bond length	0.016
RMSD bond angle	2.268
Data reduction software	XDS
Data scaling software	SCALA (3.3.22)
Phasing software	PHASER
Refinement software	REFMAC (5.8.0232)

Data quality characteristics

	Overall	Inner shell	Outer shell
Low resolution limit [Å]	60.102	50.487	2.060
High resolution limit [Å]	1.950	6.170	1.950
Rmerge		0.038	0.446
Rmeas	0.064	0.041	0.495
Rpim	0.026	0.016	0.211
Total number of observations	223462	7979	32119
Number of reflections	41566	1311	6160
<I/σ(I)>	11.2	29.8	2.2
Completeness [%]	90.7	87.5	92.4
Redundancy	5.4	6.1	5.2

Crystallization Conditions

crystal 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