7AUC

Crystal structure of an engineered helicase domain construct for human Bloom syndrome protein (BLM)

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	4O3M

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5	277.15	Morpheus-HT, condition A8, Molecular Dimensions 0.06 M divalents, 37.5% Buffer System 2 and 37.5% Precipitant Mix 4 Divalents = 0.3M magnesium chloride, 0.3M calcium chloride Buffer system 2 = 1M sodium HEPES, MOPS (acid) pH 7.5 75% Precipitant Mix 4 = 25% w/v MPD, 25% v/v PEG1000, 25% w/v PEG 3350

Crystal Properties
Matthews coefficient	Solvent content
2.38	48.39

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 54.28	α = 90
b = 107.69	β = 109.31
c = 55.2	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	100	PIXEL	DECTRIS PILATUS3 6M		2016-05-01	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	DIAMOND BEAMLINE I04	0.97794	Diamond	I04

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	CC (Half)	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	1.53	51.23	98.3	1	12.7	1.9		88499			32.58

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	CC (Half)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.53	1.56	90.3		0.61	1.2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	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	MOLECULAR REPLACEMENT	THROUGHOUT	4O3M	1.53	51.23	88464	4388	98.3	0.1901	0.1891	0.2084	RANDOM	32.6

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]
2.2284		5.847	6.3269		-8.5553

RMS Deviations
Key	Refinement Restraint Deviation
t_omega_torsion	3.72
t_other_torsion	2.37
t_angle_deg	0.9
t_bond_d	0.008
t_dihedral_angle_d
t_gen_planes
t_it
t_chiral_improper_torsion
t_sum_occupancies
t_ideal_dist_contact

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3817
Nucleic Acid Atoms
Solvent Atoms	431
Heterogen Atoms	95

Software

Software
Software Name	Purpose
BUSTER	refinement
XDS	data reduction
Aimless	data scaling
PHASER	phasing

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 R01GM133198.