7TQ0

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	2020-02-21
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.97869, 0.98062
Spacegroup name	P 2 21 21
Unit cell lengths	46.035, 74.636, 74.880
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	37.320 - 1.810
R-factor	0.1851
Rwork	0.183
R-free	0.21980
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]	45.940	1.850
High resolution limit [Å]	1.810	1.810
Rmerge	0.134	1.962
Rmeas	0.145	2.129
Rpim	0.054	0.816
Number of reflections	24175	1670
<I/σ(I)>	14.5
Completeness [%]	99.6	97.8
Redundancy	13.1	12.8
CC(1/2)	0.999	0.797

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