6OP3

Selenium incorporated FeMo-cofactor of nitrogenase from Azotobacter vinelandii with low concentration of selenium

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	2017-04-07
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.979
Spacegroup name	P 1 21 1
Unit cell lengths	80.872, 131.023, 106.957
Unit cell angles	90.00, 110.62, 90.00

Refinement procedure

Resolution	37.850 - 1.600
R-factor	0.1281
Rwork	0.127
R-free	0.15220
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	3u7q
RMSD bond length	0.015
RMSD bond angle	1.920
Data scaling software	Aimless (0.6.2)
Phasing software	MOLREP
Refinement software	REFMAC (5.8.0230)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	37.850	1.630
High resolution limit [Å]	1.600	1.600
Rmerge	0.057	0.202
Rmeas	0.068	0.243
Rpim	0.036	0.134
Total number of observations	909396	43441
Number of reflections	269898	13363
<I/σ(I)>	14.4	5.3
Completeness [%]	98.7	98.9
Redundancy	3.4	3.3
CC(1/2)	0.974	0.948

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP		291	26% v/v PEG6000, 0.75 M sodium chloride, 12.5% v/v MPD, 0.1 M imidazole/malate buffer, pH 8.0, 5 mM Na2S2O4