6H3K

Introduction of a methyl group curbs metabolism of pyrido[3,4-d]pyrimidine MPS1 inhibitors and enables the discovery of the Phase 1 clinical candidate BOS172722.

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	7.5	291.15	0.1 M Bis-Tris propane; 0.1 M MgCl2 0.1 M Sodium formate 18-26% PEG3350

Crystal Properties
Matthews coefficient	Solvent content
3.43	64.12

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 71.624	α = 90
b = 107.644	β = 90
c = 114.683	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	PIXEL	DECTRIS PILATUS 2M		2015-08-07	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	DIAMOND BEAMLINE I04-1	0.9282	Diamond	I04-1

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	Rpim I (All)	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	2.67	60.52	99.7	0.092	0.101	0.039	0.998	11.7	6.5		12793			79.3

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	Rpim I (All)	CC (Half)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	2.67	2.74	99.7		1.78	1.936	0.755	0.622		6.5

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	MOLECULAR REPLACEMENT	THROUGHOUT	2.48	41.33	16023	798	99.6	0.209	0.208	0.231	RANDOM	103.23

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]
27.1364			-14.5163		-12.6201

RMS Deviations
Key	Refinement Restraint Deviation
t_other_torsion	20.73
t_omega_torsion	2.14
t_angle_deg	1.01
t_bond_d	0.009
t_dihedral_angle_d
t_trig_c_planes
t_gen_planes
t_it
t_nbd
t_improper_torsion

RMS Deviations
Key	Refinement Restraint Deviation
t_other_torsion	20.73
t_omega_torsion	2.14
t_angle_deg	1.01
t_bond_d	0.009
t_dihedral_angle_d
t_trig_c_planes
t_gen_planes
t_it
t_nbd
t_improper_torsion
t_pseud_angle
t_chiral_improper_torsion
t_sum_occupancies
t_utility_distance
t_utility_angle
t_utility_torsion
t_ideal_dist_contact

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2003
Nucleic Acid Atoms
Solvent Atoms	37
Heterogen Atoms	40

Software

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

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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.