2J33

The Role of Loop Bundle Hydrogen Bonds in the Maturation and Activity of (Pro)caspase-3

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	8.5	291	PROTEINS WERE DIALYZED IN A BUFFER OF 10 MM TRIS-HCL, PH 8.5, 1 MM DTT. THE PROTEIN WAS CONCENTRATED TO 10 MG/ML USING AMICON ULTRAFREE CENTRIFUGAL FILTER DEVICES, AND INHIBITOR, AC-DEVD-CMK RECONSTITUTED IN DMSO, WAS THEN ADDED AT 5:1 WT:WT, INHIBITOR TO PEPTIDE. THE PROTEIN WAS DILUTED TO A CONCENTRATION OF 8 MG/ML BY ADDING 10 MM TRIS-HCL, PH 8.5, CONCENTRATED DTT AND CONCENTRATED NAN3 SO THAT THE FINAL BUFFER WAS 10 MM TRIS-HCL, PH 8.5, 10 MM DTT, 3 MM NAN3. 2 UL OF CONCENTRATED PROTEIN WAS MIXED 1:1 WITH WELL BUFFER THAT CONTAINED 100 MM SODIUM CITRATE, PH 5, 3 MM NAN3, 10 MM DTT AND 17% PEG 6000 W/V. SOLUTIONS WERE INCUBATED AT 18 DEG C USING THE HANGING DROP METHOD. CRYSTALS GREW WITHIN THREE DAYS FOR WILD- TYPE CASPASE-3 AND WITHIN TWO WEEKS FOR THE MUTANTS. THE IDEAL FREEZING CONDITIONS WERE FOUND TO BE WITH 80% MOTHER LIQUOR AND 20% PEG 400.

Crystal Properties
Matthews coefficient	Solvent content
2.2	43.72

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 67.376	α = 90
b = 83.297	β = 90
c = 95.915	γ = 90

Symmetry
Space Group	I 2 2 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			M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 22-ID		APS	22-ID

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	2	50	98.5	0.08	31.7	6.9		18581		2	11.5

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	2	2.07	97.2		0.26	7.7	6.5

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	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	THROUGHOUT	2	33.23	17892	1765	96.2	0.176	0.176	0.205	RANDOM	21.8

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]
3.41			5.3		-8.7

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	24.1
c_scangle_it	3.27
c_scbond_it	2.33
c_mcangle_it	1.79
c_angle_deg	1.3
c_mcbond_it	1.25
c_improper_angle_d	0.98
c_bond_d	0.006
c_bond_d_na
c_bond_d_prot
c_angle_d
c_angle_d_na
c_angle_d_prot
c_angle_deg_na
c_angle_deg_prot
c_dihedral_angle_d_na
c_dihedral_angle_d_prot
c_improper_angle_d_na
c_improper_angle_d_prot

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1930
Nucleic Acid Atoms
Solvent Atoms	252
Heterogen Atoms

Software

Software
Software Name	Purpose
CNS	refinement
HKL-2000	data reduction
SCALEPACK	data scaling