3J99

Structure of 20S supercomplex determined by single particle cryoelectron microscopy (State IIIb)


ELECTRON MICROSCOPY

Refinement

RMS Deviations
KeyRefinement Restraint Deviation
f_dihedral_angle_d15.881
f_angle_d1.57
f_chiral_restr0.074
f_bond_d0.009
f_plane_restr0.006
Sample
20S supercomplex consisting of truncated neuronal SNARE complex, alpha-SNAP, and N-ethylmaleimide sensitive factor (NSF)
Sample Components
N-ethylmaleimide sensitive factor
alpha Soluble NSF Attachment Protein
Syntaxin-1A
Synaptobrevin-2
Synaptosomal-associated protein 25
Specimen Preparation
Sample Aggregation StatePARTICLE
Vitrification InstrumentFEI VITROBOT MARK I
Cryogen NameETHANE
Sample Vitrification DetailsBlot for 3.5 seconds before plunging into liquid ethane (FEI VITROBOT MARK I).
3D Reconstruction
Reconstruction MethodSINGLE PARTICLE
Number of Particles14991
Reported Resolution (Å)8.2
Resolution MethodFSC 0.143 CUT-OFF
Other Details(Single particle details: 3D classification, refinement, and reconstruction were performed using RELION) (Single particle--Applied symmetry: C1)
Refinement Type
Symmetry TypePOINT
Point SymmetryC1
Map-Model Fitting and Refinement
Id1 (1NSF, 1QCS, 1N7S, 1N7S, 1N7S, 1N7S)
Refinement SpaceRECIPROCAL
Refinement ProtocolFLEXIBLE FIT
Refinement TargetR-factor
Overall B Value
Fitting Procedure
DetailsREFINEMENT PROTOCOL--flexible DETAILS--D2 domain of NSF was from crystal structure 1NSF. D1 domain of NSF was from related entry EMD-6204. N domain o ...REFINEMENT PROTOCOL--flexible DETAILS--D2 domain of NSF was from crystal structure 1NSF. D1 domain of NSF was from related entry EMD-6204. N domain of NSF was from crystal structure 1QCS. aSNAP was a homology model. SNARE complex was from crystal structure 1N7S.
Data Acquisition
Detector TypeGATAN K2 (4k x 4k)
Electron Dose (electrons/Å**2)44
Imaging Experiment1
Date of Experiment2014-01-28
Temperature (Kelvin)
Microscope ModelFEI POLARA 300
Minimum Defocus (nm)-1800
Maximum Defocus (nm)-2800
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS2.3
Imaging ModeBRIGHT FIELD
Specimen Holder ModelOTHER
Nominal Magnification31000
Calibrated Magnification
SourceFIELD EMISSION GUN
Acceleration Voltage (kV)300
Imaging Details
EM Software
TaskSoftware PackageVersion
MODEL FITTINGPHENIX
MODEL FITTINGUCSF Chimera
RECONSTRUCTIONRELION
Image Processing
CTF Correction TypeCTF Correction DetailsNumber of Particles SelectedParticle Selection Details
Each particle