ELECTRON MICROSCOPY

Sample

DnaB helicase - Lambda P helicase loader DNA replication complex

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument FEI VITROBOT MARK IV
Cryogen Name ETHANE
Sample Vitrification Details 3uL of sample was adhered to a fresh plasma cleaned grid and allowed to adsorb for 30 seconds, blotted for 3 seconds with a blot force of 4 and plunge frozen into liquid nitrogen-cooled ethane.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 90883
Reported Resolution (Å) 4.1
Resolution Method FSC 0.143 CUT-OFF
Other Details Relion was used to independently refine half sets using 0.143 gold-standard to a resolution of 4.1A. A total of 90,883 particles went into this reconstruction.
Refinement Type
Symmetry Type ?
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol FLEXIBLE FIT
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details The initial fitting was done with the 2R5U and 3BH0 models onto which the E. coli amino sequence had been built. The linker segments that connected these segments were built by hand. PHENIX real_space_refine was used to refine the complete model for the B6P5 entity.
Data Acquisition
Detector Type GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å2) 8.0
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model FEI TITAN KRIOS
Minimum Defocus (nm) -1.0
Maximum Defocus (nm) -3.0
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS 2.7
Imaging Mode BRIGHT FIELD
Specimen Holder Model FEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification 22500
Calibrated Magnification ?
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details Preliminary grid screening was performed prior to Krios data collections. All microscope alignments were completed by the New York Structural Biology SEMC team.
Imaging Experiment
Task Software Package Version
IMAGE ACQUISITION Leginon 0.0
IMAGE ACQUISITION Appion 0.0
IMAGE ACQUISITION Appion 0.0
CTF CORRECTION Gctf ?
MODEL FITTING MOLREP ?
MODEL FITTING Coot ?
SERIES ALIGNMENT RELION ?
SERIES ALIGNMENT Gautomatch ?
SERIES ALIGNMENT EMAN2 ?
RECONSTRUCTION RELION ?
SERIES ALIGNMENT TOMO3D ?
SERIES ALIGNMENT Dynamo ?
SERIES ALIGNMENT EMAN2 ?
RECONSTRUCTION Dynamo ?
MODEL REFINEMENT PHENIX ?
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION CTF correction was performed before data processing on summed micrographs using Gctf.
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