7T4H

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	2020-02-12
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.97869, 0.98062
Spacegroup name	P 2 21 21
Unit cell lengths	45.820, 74.754, 74.801
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	37.380 - 1.510
R-factor	0.169
Rwork	0.167
R-free	0.19100
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	6n4l
Data reduction software	XDS
Data scaling software	Aimless
Phasing software	MOLREP
Refinement software	PHENIX (1.19.2-4158)

Data quality characteristics

	Overall	Inner shell	Outer shell
Low resolution limit [Å]	45.790	45.790	1.530
High resolution limit [Å]	1.510	8.270	1.510
Rmerge	0.067	0.044	0.839
Rmeas	0.072	0.048	0.919
Rpim	0.028	0.020	0.366
Number of reflections	40990	305	2047
<I/σ(I)>	16.5	41.8	1.8
Completeness [%]	99.6	99.6	98.6
Redundancy	6.5	5.9	6
CC(1/2)	0.999	0.997	0.842

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