4G0C

Neutron structure of acetazolamide-bound human carbonic anhydrase II reveal molecular details of drug binding.

NEUTRON DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	3TMJ

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	9	293	1.3 M sodium citrate, 100 mM Tris, 1mM acetazolamide dissolved in DMSO (final), pH 9, VAPOR DIFFUSION, SITTING DROP, temperature 293K

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 42.84	α = 90
b = 41.76	β = 104.31
c = 72.94	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	neutron	293	PCS	3He position sensitive detector		2011-08-03	L	LAUE

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	NUCLEAR REACTOR	OTHER	0.7 - 6.5

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	2	20	84.7	0.306		3.2		14497		6.9

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	2	2.05	71.6		0.323	0.392	3.9	2.1	1830

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	R-Free Selection Details	Mean Isotropic B
NEUTRON DIFFRACTION	MIR	random	3tmj	2	20	14465	676		0.267	0.283	throughout

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	1.38
c_bond_d	0.009

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2049
Nucleic Acid Atoms
Solvent Atoms	144
Heterogen Atoms	14

Software

Software
Software Name	Purpose
PCS	data collection
nCNS	refinement
d*TREK	data reduction
SCALA	data scaling
nCNS	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.