1QM8

Structure of Bacteriorhodopsin at 100 K

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION	5.2		THE CRYSTALLIZATION CONSISTS OF TWO STEPS. FIRST, A MIXTURE OF 5 MG/ML PURPLE MEMBRANE, 0.25% OTG, 1 M AMMONIUM SULFATE, 0.16 M NACL, 0.04 M SODIUM CITRATE (PH5.2) , 0.04% NAN3 WAS INCUBATED AND 15% TREHALOSE AT 305K FOR 5 DAYS. THIS RESULTED IN THE FORMATION OF SPHERICAL VESICLES WITH A DIAMETER OF 50 NM. AFTER SEDIMENTAL MATERIALS WERE REMOVED BY CENTRIFUGATION (4000G X 10 MIN), A SUSPENSION OF THE SPHERICAL VESICLES WAS COOLED TO 278K AND CONCENTRATED BY VAPOR DIFFUSION AGAINST A RESERVOIR SOLUTION CONTAINING 2.0 M AMMONIUM SULFATE 0.08M SODIUM CITRATE (PH 5.2) AND 30% TREHALOSE. INCUBATION FOR A COUPLE OF MONTHS YIELDED HEXAGONAL CRYSTALS.

Crystal Properties
Matthews coefficient	Solvent content
3.15	60.96

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 102.1	α = 90
b = 102.1	β = 90
c = 112.3	γ = 120

Symmetry
Space Group	P 6 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	IMAGE PLATE	FUJI FILM	MIRRORS	1998-05-18	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SPRING-8 BEAMLINE BL44B2		SPring-8	BL44B2

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	2.5	46.6	100	0.057		9.9		12500			49.2

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)
1	2.5	2.65	99.9		0.387		9.9

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-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	PDB ENTRY 1BM1	2.5	8	11888	610	100	0.251	0.251	0.278	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]
-28.5	-14.2		-28.5		4.9

RMS Deviations
Key	Refinement Restraint Deviation
x_dihedral_angle_d	20.636
x_angle_deg	1.419
x_improper_angle_d	1.206
x_bond_d	0.01
x_bond_d_na
x_bond_d_prot
x_angle_d
x_angle_d_na
x_angle_d_prot
x_angle_deg_na
x_angle_deg_prot
x_dihedral_angle_d_na
x_dihedral_angle_d_prot
x_improper_angle_d_na
x_improper_angle_d_prot
x_mcbond_it
x_mcangle_it
x_scbond_it
x_scangle_it

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1759
Nucleic Acid Atoms
Solvent Atoms	23
Heterogen Atoms	257

Software

Software
Software Name	Purpose
X-PLOR	refinement
MOSFLM	data reduction
SCALA	data scaling
X-PLOR	phasing