3DU1

The 2.0 Angstrom Resolution Crystal Structure of HetL, a Pentapeptide Repeat Protein involved in Heterocyst Differentiation Regulation from the Cyanobacterium Nostoc sp. Strain PCC 7120

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5	295	0.1M HEPES, 0.7M sodium phosphate monobasic, 0.7M potassium phosphate monobasic, 12.5% glycerol, protein concentration 7.5 mg/ml, VAPOR DIFFUSION, HANGING DROP, temperature 295K

Crystal Properties
Matthews coefficient	Solvent content
2.92	57.81

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 68.2	α = 90
b = 93.763	β = 90
c = 101.307	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	BRUKER SMART 6000	mirrors	2008-02-13	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	BRUKER AXS MICROSTAR	1.54

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	1.77	68.84	89.9	0.041	61.22	38.58	32008	28767		3

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.77	1.87	58.3		0.3	0.3	4.63	38.58

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	sulfur anomalous scattering	THROUGHOUT	2	28.41	20737	1101	97.81	0.1773	0.17586	0.2042	RANDOM	17.67

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]
-0.33			0.49		-0.15

RMS Deviations
Key	Refinement Restraint Deviation
r_dihedral_angle_2_deg	24.097
r_dihedral_angle_3_deg	15.472
r_dihedral_angle_4_deg	12.169
r_scangle_it	4.76
r_dihedral_angle_1_deg	4.654
r_scbond_it	3.083
r_mcangle_it	1.511
r_angle_refined_deg	1.344
r_mcbond_it	0.965
r_symmetry_vdw_refined	0.517
r_nbtor_refined	0.308
r_nbd_refined	0.219
r_xyhbond_nbd_refined	0.146
r_symmetry_hbond_refined	0.133
r_chiral_restr	0.096
r_bond_refined_d	0.014
r_gen_planes_refined	0.005
r_bond_other_d
r_angle_other_deg
r_gen_planes_other
r_nbd_other
r_nbtor_other
r_xyhbond_nbd_other
r_metal_ion_refined
r_metal_ion_other
r_symmetry_vdw_other
r_symmetry_hbond_other
r_symmetry_metal_ion_refined
r_symmetry_metal_ion_other
r_mcbond_other
r_rigid_bond_restr
r_sphericity_free
r_sphericity_bonded

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1798
Nucleic Acid Atoms
Solvent Atoms	238
Heterogen Atoms

Software

Software
Software Name	Purpose
REFMAC	refinement
PROTEUM PLUS	data collection
SAINT	data reduction
SADABS	data scaling
SHELXS	phasing