2BG9

ELECTRON MICROSCOPY

Sample

NICOTINIC ACETYLCHOLINE RECEPTOR in postsynaptic membrane

Specimen Preperation
Sample Aggregation State HELICAL ARRAY
Vitrification Instrument ?
Cryogen Name ?
Sample Vitrification Details LIQUID ETHANE
3D Reconstruction
Reconstruction Method HELICAL
Number of Particles ?
Reported Resolution (Å) 4
Resolution Method OTHER
Other Details ?
Refinement Type
Symmetry Type HELICAL
Map-Model Fitting and Refinement
ID
Refinement Space
Refinement Protocol
Refinement Target
Overall B Value
Fitting Procedure
Details
Data Acquisition
Detector Type KODAK SO-163 FILM
Electron Dose (electrons/Å2) ?
Imaging Experiment
Date of Experiment 2000-10-01
Temprature (Kelvin)
Microscope Model JEOL 3000SFF
Minimum Defocus (nm) 800
Maximum Defocus (nm) 1800
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS 1.3
Imaging Mode BRIGHT FIELD
Specimen Holder Model .
Nominal Magnification 40000
Calibrated Magnification 36800
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details THE SPECIMENS WERE TUBULAR CRYSTALS GROWN IN LOW SALT BUFFER FROM ISOLATED TORPEDO POSTSYNAPTIC MEMBRANES. THEY WERE APPLIED TO THE MICROSCOPE GRIDS AND FROZEN IN THE SAME SOLUTION. THESE CRYSTALS WERE TOO SMALL AND DISTORTED TO YIELD MEANINGFUL ELECTRON DIFFRACTION PATTERNS, SO BOTH THE AMPLITUDE AND THE PHASE TERMS HAD TO BE MEASURED FROM FOURIER TRANSFORMS OF THE IMAGES. THE IMAGES WERE RECORDED USING A DOSE OF 2000 ELECTRONS/NM2 DURING THE PERIOD: JAN-1996 TO OCT-2002. THE DATASETS INVOLVED 4 HELICAL FAMILIES OF TUBES. STRUCTURES WERE SYNTHESISED FROM THE AMPLITUDE AND PHASE TERMS DERIVED FROM EACH FAMILY. THE FINAL DATASET WAS OBTAINED BY AVERAGING THESE 4 STRUCTURES IN REAL SPACE.
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details