3QTL

Structural Basis for Dual-inhibition Mechanism of a Non-classical Kazal-type Serine Protease Inhibitor from Horseshoe Crab in Complex with Subtilisin

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6.5	298	11% (w/v) PEG 20000, 0.1M 2-(N-morpholino)ethanesulfonic acid (MES) pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K

Crystal Properties
Matthews coefficient	Solvent content
2.97	58.53

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 73.84	α = 90
b = 65.072	β = 95.44
c = 111.909	γ = 90

Symmetry
Space Group	P 1 21 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	298				2007-09-29	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	NSLS BEAMLINE X29A	1.5418	NSLS	X29A

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Sym 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	2.6	15	99.8	0.1		6.3		32884	2	2

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	2.6	2.64	99.3		0.34		5.3

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	PDB ENTRY 1SCA	2.6	14.901	0.14	32432	1973	99.36	0.2036	0.1994	0.2691	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]
-8.3136		-0.1614	-2.6434		10.957

RMS Deviations
Key	Refinement Restraint Deviation
f_dihedral_angle_d	15.846
f_angle_d	0.82
f_chiral_restr	0.055
f_bond_d	0.004
f_plane_restr	0.003

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	6244
Nucleic Acid Atoms
Solvent Atoms	157
Heterogen Atoms

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
MOLREP	phasing
REFMAC	refinement
PDB_EXTRACT	data extraction
CBASS	data collection
PHENIX	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.