ELECTRON MICROSCOPY

Sample

YEAST POL II TRANSCRIPTION INITIATION COMPLEX (OPEN DNA)

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument FEI VITROBOT MARK IV
Cryogen Name ETHANE
Sample Vitrification Details CRYOGEN - ETHANE. INSTRUMENT - FEI VITROBOT MARK IV. QUANTIFOIL R 3.5- 1 HOLEY CARBON GRIDS WERE GLOW-DISCHARGED BEFORE DEPOSITION OF 4.5 MICROLITERS OF SAMPLE. GRIDS WERE THEN BLOTTED FOR 8.5 S AND PLUNGE- FROZEN IN LIQUID ETHANE.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 11231
Reported Resolution (Å) 4.35
Resolution Method ?
Other Details RESIDUES INDICATED AS POLY-ALANINE ARE OF UNCERTAIN AMINO ACID REGISTER. THE FOLLOWING REGIONS WERE MODELED INTO THE INDICATED UNSHARPENED MAP DUE TO WEAKER DENSITY. RPB2 RESIDUES 919-932 (OC1, EMD-3375). TFIIF SUBUNIT TFG1 RESIDUES 327-330 (POLY-ALANINE) AND 404-415 (POLY-ALANINE) (OC4, EMD-3380). TFIIF SUBUNIT TFG2 RESIDUES 233-244 (POLY- ALANINE) (OC4, EMD-3380). TFIIE SUBUNITS TFA1 (POLY- ALANINE) AND TFA2 (POLY-ALANINE) AND TFIIF SUBUNIT TFG2 WINGED HELIX DOMAIN RESIDUES 294-352 (POLY-ALANINE) (OC3, EMD-3378 AND OC3-FOCUSED, EMD-3379). TFIIF SUBUNIT TFG2 WINGED HELIX DOMAIN RESIDUES 359-370 (UNK) WERE PUTATIVELY ASSIGNED TO TFG2 (OC3-FOCUSED, EMD-3379). TFIIE SUBUNIT TFA2 RESIDUES 256-280 SHOW UNCERTAIN CONNECTIVITY. THE SEQUENCE OF THE TFIIF TFG2 LINKER (RESIDUES 249-280) WAS ASSIGNED BASED ON THE STRONG SIDECHAIN DENSITY OF RESIDUES I252, L255, F277, L278 AND THEIR FIT TO THE LOCAL CHEMICAL ENVIRONMENT. TFIIF SUBUNIT TFG1 RESIDUES 21-35 WERE MODELED BASED ON A SEPARATE X-RAY ANALYSIS (PDB 5IP7) AND FITTED (OC4 ROUND 2 CLASS 2). SUBMISSION BASED ON EXPERIMENTAL DATA FROM EMDB EMD-3378. (DEPOSITION ID: 14360).
Refinement Type
Symmetry Type POINT
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol OTHER
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details REFINEMENT PROTOCOL--CRYO-EM
Data Acquisition
Detector Type GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å2) 33
Imaging Experiment
Date of Experiment 2016-04-26
Temprature (Kelvin)
Microscope Model FEI TITAN KRIOS
Minimum Defocus (nm) 700
Maximum Defocus (nm) 4200
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS 2.3
Imaging Mode BRIGHT FIELD
Specimen Holder Model .
Nominal Magnification 37000
Calibrated Magnification 37037
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details ?
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
? EACH PARTICLE