4G0C

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

NEUTRON DIFFRACTION

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 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.