6NTT

X-ray Crystal Structure of Soybean Trypsin Inhibitor (Kunitz) Complexed with 1,5-Disulfonyl Naphthalene

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	SSRL BEAMLINE BL7-1
Synchrotron site	SSRL
Beamline	BL7-1
Temperature [K]	173
Detector technology	CCD
Collection date	2012-06-20
Detector	MAR CCD 130 mm
Wavelength(s)	1.0
Spacegroup name	P 1 21 1
Unit cell lengths	41.880, 64.680, 69.080
Unit cell angles	90.00, 97.52, 90.00

Refinement procedure

Resolution	32.610 - 2.400
R-factor	0.21376
Rwork	0.209
R-free	0.30595
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1avu
RMSD bond length	0.005
RMSD bond angle	1.284
Data reduction software	CrystalClear
Data scaling software	CrystalClear
Phasing software	PHASER
Refinement software	REFMAC (5.8.0238)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	32.610	2.450
High resolution limit [Å]	2.400	2.400
Rmerge	0.122	0.481
Rmeas	0.136	0.538
Number of reflections	13649
<I/σ(I)>	4.7	2.2
Completeness [%]	99.0	85
Redundancy	4.7	4.5
CC(1/2)	0.990

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP	6.5	293	Lyophilized protein dissolved in water to 25 mg/ml. Sitting drop vapor diffusion against reservoirs of 25% PEG 3350 with 0.10 M MES buffer ph 6.5. 3 ul drops composed of equal amounts of protein stock solution and reservoir supplemented with 0.10 M 1,5-Disulfonyl Naphthalene. Crystallization time about 2 weeks.