Experiment: 1KFF

An engineered streptavidin with improved affinity for the strep-tag II peptide: apo-SAM1

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1SWU

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.3	293	100 mM Na2HPO4, 1.2-M (NH4)2SO4, pH 7.3, VAPOR DIFFUSION, HANGING DROP, temperature 293K

Crystal Properties
Matthews coefficient	Solvent content
2.2	44

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 58.419	α = 90
b = 86.916	β = 98.9
c = 47.196	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	IMAGE PLATE	MARRESEARCH	osmic mirrors	2001-01-10	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU300	1.5418

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	1.9	41.1	89.2	0.051	13.2	1.6	33063	33063		-3	24.705

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)
	1.9	1.97	85.5		0.311	1.9	1.5	3143

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	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	FOURIER SYNTHESIS	1swu	1.9	41.1	32808	32808	1650	89.3	0.17314	0.17016	0.1832	0.22917	0.2404	RANDOM	25.428

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]
-1.17		-0.05	1.37		-0.21

RMS Deviations
Key	Refinement Restraint Deviation
p_angle_d	2.868
p_bond_d	0.016

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3588
Nucleic Acid Atoms
Solvent Atoms	212
Heterogen Atoms

Software

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