3F8G

The X-ray structure of a dimeric variant of human pancreatic ribonuclease with high cytotoxic and antitumor activities

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1E21	PDB entry 1E21, the crystal structure of des(1-7)RNase

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP		277	A protein solution of 10mg/ml in 10mM Tris acteate ph 7.0, 300mM NaCl was equilibrated against a solution containing 27% w/v PEG, 0.2 M AS, and 100mM cacodylate buffer ph 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 277K

Crystal Properties
Matthews coefficient	Solvent content
2.56	52.04

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 45.855	α = 90
b = 78.256	β = 90
c = 80.695	γ = 90

Symmetry
Space Group	P 21 21 21

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	MAR CCD 165 mm	mirrors	2005-10-14	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	ELETTRA BEAMLINE 5.2R	1.00	ELETTRA	5.2R

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	2.6	40	98.7	0.09	20			9128

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	PDB entry 1E21, the crystal structure of des(1-7)RNase	2.6	40	2	8980	8539	462	90.9	0.215	0.306	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]

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1954
Nucleic Acid Atoms
Solvent Atoms	162
Heterogen Atoms	25

Software

Software
Software Name	Purpose
AMoRE	phasing
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), 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 R01GM157729.