1LOK

The 1.20 Angstrom Resolution Crystal Structure of the Aminopeptidase from Aeromonas proteolytica Complexed with Tris: A Tale of Buffer Inhibition

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	8	295	Tris, potassium thiocyanate, sodium chloride, pH 8.0, VAPOR DIFFUSION, HANGING DROP, temperature 295K

Crystal Properties
Matthews coefficient	Solvent content
2.52	51.18

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 108.338	α = 90
b = 108.338	β = 90
c = 93.519	γ = 120

Symmetry
Space Group	P 61 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	CCD	ADSC QUANTUM 4		2000-02-11	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 14-BM-C	1.0000	APS	14-BM-C

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (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	0.94	27.08	88.4		15	89053	89053

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	0.94	1.25	98

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 (All)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	FOURIER SYNTHESIS	THROUGHOUT	PDB ENTRY 1AMP	1.2	27.08	89053	89053	9943		0.154	0.145	0.158	0.198	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
s_zero_chiral_vol	0.082
s_anti_bump_dis_restr	0.08
s_angle_d	0.032
s_from_restr_planes	0.0289
s_bond_d	0.018

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2251
Nucleic Acid Atoms
Solvent Atoms	348
Heterogen Atoms	14

Software

Software
Software Name	Purpose
SHELXL-97	refinement
SCALEPACK	data scaling
CNS	refinement
DENZO	data reduction
CNS	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.