6N4K

Dithionite-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	2017-07-21
Detector	DECTRIS PILATUS 6M
Wavelength(s)	1.0
Spacegroup name	C 1 2 1
Unit cell lengths	103.620, 45.199, 108.772
Unit cell angles	90.00, 96.58, 90.00

Refinement procedure

Resolution	39.290 - 1.756
R-factor	0.1729
Rwork	0.171
R-free	0.21300
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1g5p
RMSD bond length	0.008
RMSD bond angle	1.703
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]	108.055	39.257	1.850
High resolution limit [Å]	1.756	5.550	1.756
Rmerge		0.040	0.208
Rmeas	0.049	0.043	0.228
Rpim	0.019	0.017	0.092
Total number of observations	323888	11103	33873
Number of reflections	48484	1656	5912
<I/σ(I)>	22	42.7	5.9
Completeness [%]	96.5	98.5	81.8
Redundancy	6.7	6.7	5.7

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP	6.5	298	of 40% PEG 1000, 0.2 M NaCl, 0.1 M MES/OH pH 6.5, 10% 2,2,2-trifluoroethanol, 5 mM dithionite