7KX9 | pdb_00007kx9

Cryo-EM structure of Ephydatia fluviatilis PiwiA-piRNA-target complex

ELECTRON MICROSCOPY

---

Sample
EfPiwi-piRNA-target complex
Sample Components
Piwi-A
piRNA-target

Specimen Preparation
Sample Aggregation State	PARTICLE
Vitrification Instrument	HOMEMADE PLUNGER
Cryogen Name	ETHANE
Sample Vitrification Details	Freezing was carried out in a cold room at 4 degree C and relative humidity between 95%-98%. 3.5 uL sample was applied to plasma cleaned grid and manually blotted with Whatman 1 filter paper for 5-7 sec before plunge freezing in liquid ethane at -179 degree C.

3D Reconstruction
Reconstruction Method	SINGLE PARTICLE
Number of Particles	118493
Reported Resolution (Å)	3.5
Resolution Method	FSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry Type	POINT
Point Symmetry	C1

Map-Model Fitting and Refinement
Id	1
Refinement Space
Refinement Protocol
Refinement Target
Overall B Value
Fitting Procedure
Details

Data Acquisition
Detector Type	GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å**2)	47.33

Imaging Experiment	1
Date of Experiment
Temperature (Kelvin)
Microscope Model	FEI TALOS ARCTICA
Minimum Defocus (nm)	1000
Maximum Defocus (nm)	1600
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	36000
Calibrated Magnification	43478
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	200
Imaging Details

EM Software
Task	Software Package	Version
PARTICLE SELECTION	RELION	2
IMAGE ACQUISITION	Leginon
CTF CORRECTION	CTFFIND	4
MODEL REFINEMENT	PHENIX
INITIAL EULER ASSIGNMENT	RELION	2
FINAL EULER ASSIGNMENT	RELION	2
RECONSTRUCTION	RELION	2.0

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION		2551046	Laplacian of Gaussian based automated particle picking program in RELION was used.