7TEV

Human Ornithine Aminotransferase cocrystallized with its inhibitor, (3S,4R)-3-amino-4-(difluoromethyl)cyclopent-1-ene-1-carboxylate

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	APS BEAMLINE 21-ID-D
Synchrotron site	APS
Beamline	21-ID-D
Temperature [K]	100
Detector technology	PIXEL
Collection date	2020-09-20
Detector	DECTRIS EIGER X 9M
Wavelength(s)	1.127
Spacegroup name	P 32 2 1
Unit cell lengths	115.827, 115.827, 187.412
Unit cell angles	90.00, 90.00, 120.00

Refinement procedure

Resolution	44.220 - 1.910
R-factor	0.2571
Rwork	0.256
R-free	0.26900
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1oat
RMSD bond length	0.012
RMSD bond angle	1.567
Data reduction software	autoPROC
Data scaling software	Aimless
Phasing software	PHASER
Refinement software	PHENIX (1.19.2_4158)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	88.438	1.940
High resolution limit [Å]	1.907	1.907
Number of reflections	113351	5443
<I/σ(I)>	10.6
Completeness [%]	99.8
Redundancy	12.7
CC(1/2)	0.998	0.296

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	7.8	293	After purification, hOAT was buffer exchanged into the crystallization buffer (50 mM Tricine pH 7.8) supplemented with 1 mM 2-ketoglutarate. The protein was concentrated to 6.5 mg/mL. Previously reported crystallization conditions were optimized using the hanging drop vapor diffusion method by varying PEG 6000 (8-12%), NaCl (100-250 mM), and glycerol (0%-10%) with 100 mM Tricine pH 7.8 being kept constant as the buffer. For each hanging drop, 2 uL of protein solution was mixed with an equal volume of well solution and 0.5 uL of ligand. The crystals with the best morphology and size grew in a final condition containing 12% PEG 6000, 200 mM NaCl, 10% glycerol, and 100 mM Tricine pH 7.8. Crystals were transferred to a cryo-protectant solution (well solution supplemented with 30% glycerol) and flash-frozen in liquid nitrogen.