2BD1

A possible role of the second calcium ion in interfacial binding: Atomic and medium resolution crystal structures of the quadruple mutant of phospholipase A2

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1UNE	1UNE, 1MKT
experimental model	PDB	1MKT	1UNE, 1MKT

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION	7.2	293	The crystallization droplet contained 5 micro litre of protein (18 to 20 mg/ml) in 50 mM tris buffer with 2 micro litre of MPD (60%) and the reservoir contained 70% of MPD., pH 7.2, VAPOR DIFFUSION, temperature 293K

Crystal Properties
Matthews coefficient	Solvent content
2.17	43.24

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 74.58	α = 90
b = 48.69	β = 102.3
c = 67.55	γ = 90

Symmetry
Space Group	C 1 2 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	293	IMAGE PLATE	RIGAKU			M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	MACSCIENCE	1.5418

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge 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	1.9	14.69	94.7	0.093			13356	13356

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	1.9	1.99			0.458			1507

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 (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	1UNE, 1MKT	1.9	14.69	13340	1071	94.7	0.207	0.2	0.24	0.24	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]
-0.15		-0.28	0.49		-0.34

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1906
Nucleic Acid Atoms
Solvent Atoms	234
Heterogen Atoms	4

Software

Software
Software Name	Purpose
MAR345	data collection
SCALEPACK	data scaling
AMoRE	phasing
CNS	refinement

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.