8Q50

Nitrogenase Fe protein from Methanothermococcus thermolithotrophicus, tetragonal crystalline form at 1.91-A resolution

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	SOLEIL BEAMLINE PROXIMA 1
Synchrotron site	SOLEIL
Beamline	PROXIMA 1
Temperature [K]	100
Detector technology	PIXEL
Collection date	2019-11-22
Detector	DECTRIS EIGER X 16M
Wavelength(s)	1.74013
Spacegroup name	P 43 21 2
Unit cell lengths	98.895, 98.895, 61.149
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	52.010 - 1.910
R-factor	0.2032
Rwork	0.202
R-free	0.23050
Structure solution method	MOLECULAR REPLACEMENT
RMSD bond length	0.013
RMSD bond angle	1.431
Data reduction software	autoPROC
Data scaling software	autoPROC
Phasing software	PHASER
Refinement software	PHENIX ((1.20.1_4487: ???))

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	52.010	1.940
High resolution limit [Å]	1.910	1.910
Rmerge	0.159	3.120
Rmeas	0.161	3.190
Rpim	0.025	0.644
Number of reflections	24200	1183
<I/σ(I)>	15.9	1.4
Completeness [%]	100.0	100
Redundancy	41.2	23.9
CC(1/2)	0.997	0.616

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP	4.6	293.15	The purified protein was crystallised at a final concentration of 6 mg/ml by spotting 0.5 ul of crystallisation solution with 0.5 ul of protein sample. Crystallization was done anaerobically in a Coy tent containing N2/H2 (97:3%) atmosphere. The screening was done at 20 degrees Celsius on 96-Well MRC 2-drop polystyrene (SWISSCI) plates containing 90 ul of crystallization solution. The crystallisation solution in which crystals were obtained contained 30 % v/v 2-methyl-2,4-pentanediol, 100 mM sodium acetate, pH 4.6 and 20 mM calcium chloride.