Experiment: 2DPQ

The crystal structures of the calcium-bound con-G and con-T(K7gamma) dimeric peptides demonstrate a novel metal-dependent helix-forming motif

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
in silico model	Other		14-mer polyalanine helix

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	8		35% dioxane, pH 8, VAPOR DIFFUSION, HANGING DROP

Crystal Properties
Matthews coefficient	Solvent content
2.23	44.76

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 29.334	α = 90
b = 29.334	β = 90
c = 46.892	γ = 90

Symmetry
Space Group	P 42 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	277	CCD	MAR CCD 165 mm		2003-05-12	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 32-ID	1.0	APS	32-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	1.2	50	98	0.081	7.1			12427		-3

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	1.2	1.24	94.4		0.923			611

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 (All)	R-Factor (Observed)	R-Work (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	14-mer polyalanine helix	1.25	8	2	6727			0.121	0.119	0.119	0.1404	0.161	0.1851	Random	27.161

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]

RMS Deviations
Key	Refinement Restraint Deviation
x_angle_d	0.024
x_bond_d	0.01

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	158
Nucleic Acid Atoms
Solvent Atoms	67
Heterogen Atoms	4

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
SHELX	refinement
PDB_EXTRACT	data extraction
PHASER	phasing
SHELXL	refinement