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Import/export tomography data

Import/export tomography data

1 Import tomography data in star format

Attention

Importing data from Relion to pyp requires enabling FlipYZ and FlipZ when running Relion Import Tomograms job. If not, particle coordinates won’t be converted correctly.

Requirements

  • Absolute path to star file from 3D refinement jobs (*_data.star)

  • Absolute path to star file from Import Tomograms job (ImportTomo/{job_id}/tomograms.star)

  • Absolute path to Relion project folder

  • Tilt-series files in correct relative path as indicated in the tomogram star file

  • Corresponding tilt-series parameter files (*.xf, *.tlt and *.com) in the same folder with tilt-series files

Note

  • *.xf, *.tlt are alignment parameters, which are required for each tilt-series.

  • *.com is optional. If they are not present, we would assume NO x or z shift applied to the tomograms. This might affect the outcome of particle coordinate conversion.

Procedure

To import tomography data from Relion:

# creat an empty folder for importing
mkdir demo_import

cd demo_import

# run import
rlp -import_refine_star "/path/to/run_it000_data.star"  \
    -import_tomo_star "/path/to/tomograms.star"         \
    -import_relion_path "/path/to/relion/project"       \
    -import_read_star                                   \
    -scope_pixel 1.35                                   \
    -scope_voltage 300                                  \
    -data_path "/path/to/tiltseries/folder/*.mrc"       \
    -data_mode tomo

Running the command above will generate particle alignment parameter file (pyp_update_volumes.txt) and metadata (meta/*.pkl). We suggest you to run an iteration of csp to make sure they are correctly converted.

csp -refine_parfile="$(pwd)/pyp_update_volumes.txt"     \
    -refine_model="/path/to/relion/map"                 \
    -particle_mw 200                                    \
    -particle_rad 150                                   \
    -extract_box 256                                    \
    -extract_bin 1                                      \
    -refine_skip                                        \
    -refine_iter 2                                      \
    -refine_maxiter 2

2 Export tomography data in star format

Requirements

  • A parfile generated by running csp (frealign/maps/export_demo_r01_02.par.bz2)

  • Metadata generated by running tomo preprocessing (meta/*.pkl)

Procedure

To export data from pyp to Relion:

# go to pyp project directory
cd demo_export

# simply run export relion command
csp -export_enable                              \
    -export_parfile "path_to_your_parfile"      \
    -export_location "path_to_export_location"

After completing the procedure above, tomogram star file (demo_export_tomograms.star) and refinement star file (demo_export_particles.star) will be produced in the relion folder. It’s ready to run Relion from Import Coordinates using the star files we just generated.

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