6SMN

A. thaliana serine hydroxymethyltransferase isoform 2 (AtSHMT2) in complex with methotrexate

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	6CD0

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5	292	3 uL of the protein solution and 2 uL of reservoir solution: 90% Hampton Research Index F8 (0.2 M ammonium sulfate, 0.1 M Hepes pH 7.5, and 25% polyethylene glycol 3350). Mature crystals were transferred to drops with the original screen conditions supplemented with 20% ethylene glycol, 50 mM L-serine, and 10 mM MTX. After 24-h incubation, crystals were harvested and vitrified in liquid nitrogen.

Crystal Properties
Matthews coefficient	Solvent content
2.64	53.37

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 115.031	α = 90
b = 130.401	β = 90
c = 150.826	γ = 90

Symmetry
Space Group	P 21 21 21

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	RAYONIX MX300-HS		2018-08-10	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 22-BM	1.0000	APS	22-BM

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	Rrim 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	1.63	80	99.8	0.087	0.093	1	18.3	8.2		279297

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	CC (Half)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.63	1.73	98.5		1.16	1.24	0.7	2	7.8

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-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	FREE R-VALUE	6cd0	1.63	80	277883	1396	99.8	0.125	0.177

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
angles	0.8
bonds	0.005

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	14952
Nucleic Acid Atoms
Solvent Atoms	1922
Heterogen Atoms	397

Software

Software
Software Name	Purpose
PHENIX	refinement
XDS	data reduction
XDS	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 R01GM157729.