7TQ9

Selenium-incorporated nitrogenase Fe protein (Av2-Se) from A. vinelandii (22 mM KSeCN, with Av1)

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	2020-01-24
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.97239, 0.98062
Spacegroup name	P 2 21 21
Unit cell lengths	45.835, 74.406, 74.689
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	39.020 - 1.600
R-factor	0.1723
Rwork	0.171
R-free	0.19420
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	6n4l
Data reduction software	XDS
Data scaling software	Aimless (0.7.7)
Phasing software	MOLREP
Refinement software	PHENIX (1.19.2-4158)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	45.850	1.630
High resolution limit [Å]	1.600	1.600
Rmerge	0.055	0.902
Rmeas	0.064	1.070
Rpim	0.034	0.568
Number of reflections	34297	1623
<I/σ(I)>	14.1
Completeness [%]	99.5	97.1
Redundancy	6.6	6.5
CC(1/2)	0.999	0.851

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP	7.5	298	36-41% PEG400, 0.1-0.3 M sodium chloride, 0.1 M HEPES, pH 7.5, 2.5 mM dithionite, 0.17 mM Cymal-7