Experiment: 2DPR

The crystal structures of the calcium-bound con-G and con-T(K7Glu) 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	5.5	277	3M (NH4)2SO4, 0.1M NaOAc, pH 5.5, VAPOR DIFFUSION, HANGING DROP, temperature 277K

Crystal Properties
Matthews coefficient	Solvent content
5.38	77.12

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 89.013	α = 90
b = 89.013	β = 90
c = 89.013	γ = 90

Symmetry
Space Group	P 43 3 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		2005-07-12	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 31-ID	1.0	APS	31-ID

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (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	1.6	40	99.5				16448		-3

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.6	1.66	100				1614

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	1.7	10	2	16448			0.14	0.133	0.133	0.1683	0.186	0.2023	random	36.578

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_deg	0.033
x_bond_d	0.011

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	378
Nucleic Acid Atoms
Solvent Atoms	142
Heterogen Atoms	4

Software

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