1LU0

Atomic Resolution Structure of Squash Trypsin Inhibitor: Unexpected Metal Coordination

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6.5	293	PEG 8000, zinc sulfate, cacodylate, MPD, pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 293.0K

Crystal Properties
Matthews coefficient	Solvent content
2.23	44.8

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 47.28	α = 90
b = 58.63	β = 90
c = 19.32	γ = 90

Symmetry
Space Group	P 21 21 2

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	CCD	MARRESEARCH		2000-04-07	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	EMBL/DESY, HAMBURG BEAMLINE BW7A	0.8919	EMBL/DESY, HAMBURG	BW7A

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	Net I Over Average Sigma (I)	Redundancy	Number Reflections (All)	Number Reflections (Observed)	Observed Criterion Sigma (F)	Observed Criterion Sigma (I)	B (Isotropic) From Wilson Plot
1	1.03	15	99.2	0.047	30.7	9.3	27045	27045		-3	12.9

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.03	1.07	98.3		0.151	2.73	3.5	2637

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Cut-off Sigma (I)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (All)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	Dual-space recycling	FREE R	1.03	10	-3	26990	26990	1345	99.1	0.1206	0.1206	0.12	0.1449	RANDOM

Temperature Factor Modeling
Anisotropic B[1][1]	Anisotropic B[1][2]	Anisotropic B[1][3]	Anisotropic B[2][2]	Anisotropic B[2][3]	Anisotropic B[3][3]

Coordinate Error
Structure Solution Method	Refinement High Resolution	Refinement Low Resolution
5	432	517.49

RMS Deviations
Key	Refinement Restraint Deviation
s_non_zero_chiral_vol	0.13
s_zero_chiral_vol	0.106
s_approx_iso_adps	0.091
s_similar_adp_cmpnt	0.056
s_angle_d	0.039
s_from_restr_planes	0.031
s_bond_d	0.025
s_rigid_bond_adp_cmpnt	0.006
s_similar_dist
s_anti_bump_dis_restr

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	444
Nucleic Acid Atoms
Solvent Atoms	76
Heterogen Atoms	24

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
SHELXD	phasing
SHELXL-97	refinement

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.