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 4AQ5 | pdb_00004aq5

Gating movement in acetylcholine receptor analysed by time-resolved electron cryo-microscopy (closed class)


ELECTRON MICROSCOPY

Starting Model(s)

Initial Refinement Model(s)
TypeSourceAccession CodeDetails
experimental modelPDB 2BG9 
Sample
NICOTINIC ACETYLCHOLINE RECEPTOR IN NATIVE POSTSYNAPTIC MEMBRANE FROM TORPEDO MARMORATA
Specimen Preparation
Sample Aggregation StateHELICAL ARRAY
Vitrification InstrumentHOMEMADE PLUNGER
Cryogen NameETHANE
Sample Vitrification DetailsVITRIFICATION 1 -- CRYOGEN- ETHANE, HUMIDITY- 85 TEMPERATURE- 120 INSTRUMENT- HOMEMADE PLUNGER METHOD- BLOT UNTIL APPLIED DROPLET LOSES CONTACT WITH F ...VITRIFICATION 1 -- CRYOGEN- ETHANE, HUMIDITY- 85 TEMPERATURE- 120 INSTRUMENT- HOMEMADE PLUNGER METHOD- BLOT UNTIL APPLIED DROPLET LOSES CONTACT WITH FILTER PAPER (INDICATED BY LOSS OF TRANSPARENCY TYPICALLY 6S) TIMERESOLVEDSTATE- VITRIFIED WITHIN 10MS OF EXPOSURE TO ACETYLCHOLINE (APPLIED AS THE GRID IS BEING PLUNGED USING A FINE FOCUSSED SPRAY POSITIONED ABOUT 1CM ABOVE THE ETHANE SURFACE) DETAILS- VITRIFICATION CARRIED OUT AT AN AMBIENT TEMPERATURE OF 8 DEGREES
3D Reconstruction
Reconstruction MethodHELICAL
Number of Particles
Reported Resolution (Å)6.2
Resolution Method
Other DetailsFOURIER-BESSEL SYNTHESIS AFTER APPLYING DISTORTION CORRECTIONS TO THE IMAGES. SUBMISSION BASED ON EXPERIMENTAL DATA FROM EMDB EMD-2071.
Refinement Type
Symmetry TypeHELICAL
Map-Model Fitting and Refinement
Id1 (2BG9)
Refinement SpaceREAL
Refinement ProtocolFLEXIBLE FIT
Refinement Target
Overall B Value
Fitting Procedure
DetailsMETHOD--MAXIMISATION OF CORRELATION BETWEEN EXPERIMENTAL DENSITIES AND ATOMIC MODEL, USING A DEFORMABLE ELASTIC NETWORK ALGORITHM (DIREX) REFINEMENT ...METHOD--MAXIMISATION OF CORRELATION BETWEEN EXPERIMENTAL DENSITIES AND ATOMIC MODEL, USING A DEFORMABLE ELASTIC NETWORK ALGORITHM (DIREX) REFINEMENT PROTOCOL--LOW RESOLUTION X-RAY
Data Acquisition
Detector TypeKODAK SO-163 FILM
Electron Dose (electrons/Å**2)25
Imaging Experiment1
Date of Experiment2005-11-01
Temperature (Kelvin)4
Microscope ModelJEOL 3000SFF
Minimum Defocus (nm)900
Maximum Defocus (nm)2000
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS1.6
Imaging ModeBRIGHT FIELD
Specimen Holder Model
Nominal Magnification40000
Calibrated Magnification38500
SourceFIELD EMISSION GUN
Acceleration Voltage (kV)300
Imaging DetailsSTANDARD LOW DOSE IMAGING OF SPECIMENS OVER HOLES IN THE CARBON SUPPORT FILM
EM Software
TaskSoftware PackageVersion
MODEL FITTINGDireX
RECONSTRUCTIONCustom
RECONSTRUCTIONMRC IMAGE PROCESSING PACKAGE
Image Processing
CTF Correction TypeCTF Correction DetailsNumber of Particles SelectedParticle Selection Details
EACH TUBE IMAGE