ELECTRON MICROSCOPY

Sample

DOUBLE-STRANDED TARGET DNA ENGAGED CSY COMPLEX FROM PSEUDOMONAS AERUGINOSA (PA-14)

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument HOMEMADE PLUNGER
Cryogen Name ETHANE
Sample Vitrification Details Freezing was carried out in a cold room at 4 degrees C and relative humidity of 98%. 5 ul sample was applied to plasma cleaned grid and manually blotted with Whatman 1 filter paper for 5-7 sec before plunge freezing.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 291227
Reported Resolution (Å) 3.400
Resolution Method FSC 0.143 CUT-OFF
Other Details The final map was reconstructed using several focused maps from different sub-regions of the complex. These were initially aligned to each other and then stitched using the vop maximum function in UCSF chimera. The resolution of the final composite map is 3.2 angstrom.
Refinement Type
Symmetry Type POINT
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol AB INITIO MODEL
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details THE ATOMIC MODELS FOR CAS5F, CAS8F, CAS6F, AND CAS7F FROM THE CSY ACR COMPLEX (PDB ID 5UZ9) WERE USED AS INITIAL TEMPLATE MODELS FOR MODEL BUILDING. THESE WERE INDIVIDUALLY RIGID BODY-FITTED INTO THE RECONSTRUCTED MAPS USING THE FIT MAP FUNCTION IN UCSF CHIMERA, AND RESIDUE REGISTERS AND BACKBONE GEOMETRIES WERE FIXED IN COOT. MODELS FOR THE CRRNA AND DNA STRANDS WERE ALSO MANUALLY BUILT INTO THE MAP USING COOT.
Data Acquisition
Detector Type GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å2) 0.58
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model FEI TALOS ARCTICA
Minimum Defocus (nm) 600.00
Maximum Defocus (nm) 1500.00
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS 2.70
Imaging Mode BRIGHT FIELD
Specimen Holder Model ?
Nominal Magnification 36000
Calibrated Magnification ?
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 200
Imaging Details OBJECTIVE ASTIGMATISM WAS CORRECTED AT 36000X MAGNIFICATION USING THON RINGS VISUALIZED WITH A K2 CAMERA.
Imaging Experiment
Task Software Package Version
IMAGE ACQUISITION Leginon ?
CTF CORRECTION CTFFIND 4
INITIAL EULER ASSIGNMENT RELION 2.1
FINAL EULER ASSIGNMENT RELION 2.1
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION ?