2E7F

5-methyltetrahydrofolate corrinoid/iron sulfur protein methyltransferase complexed with methyltetrahydrofolate to 2.2 Angsrom resolution

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1F6Y	PDB ENTRY 1F6Y

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5	298	8-15% PEGmme 5000, 0.05M Calcium acetate, 20% Glycerol, 0.05M HEPES buffer; 3-fold molar excess of the MTHF substrate (Schricks Labolatories, Jona, Switzerland). The supersaturation of the precipitant solution required dilution of the protein-CH3-H4folate complex by 50-100-fold in order to obtain single crystals., pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.33	47.24

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 50.159	α = 90
b = 78.547	β = 90
c = 135.617	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	BRANDEIS - B4		2000-07-30	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	NSLS BEAMLINE X12C	0.91938	NSLS	X12C

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (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	2.2	30.92	96.2	0.086	0.086	11.5	3.8		26806			14.8

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)
	2.2	2.26	87.9		0.206	3.5	3.5	1750

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation 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	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	PDB ENTRY 1F6Y	2.2	30.88	26763	24177	2586	96.04	0.178	0.172	0.23	RANDOM

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
c_angle_deg	1.018
c_bond_d	0.006

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3994
Nucleic Acid Atoms
Solvent Atoms	435
Heterogen Atoms	68

Software

Software
Software Name	Purpose
CBASS	data collection
EPMR	phasing
CNS	refinement
MOSFLM	data reduction
CCP4	data scaling

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.