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Omokage search
- Shape similarity search of macromolecules -

Search query

Query structure data:

  • EMDB map
    4 digit ID (or string starts with "e") (e.g.1003, EMD-1003, e1003)
  • PDB deposited unit (asymetric unit, AU)
    4 letter ID code (or + "-d") (e.g.100d, 100d-d)
  • PDB assembly (biological unit, BU)
    ID + hyphen + assembly-ID (e.g.1oel-1)
    Or click the image of AU/BU, which will be shown below when you input an PDB-ID
  • SASBDB model
    SASBDB-ID or model-ID (e.g.SASDAA5, 100, sas-100)
  • Comparison of 3 databanks


Structure data giving symbolic results

This is an EM map data of the RNA polymerase II at 25 A resolution. You will find atomic models and EM maps of RNA polymerase structures from the EMDB & PDB. Perform search.

The DNA clamp is a ring shaped oligomer essential for DNA metabolism. All the DNA clamps have similar shapes, while bacterial clamps are dimer ring, and archaeal/eukaryal ones are trimer ring. By search using this trimer clamp, you will find dimer clamp structures as well. Perform search.

EF-Tu/tRNA complex (RNA + protein) and EF-G (monomeric protein) have similar shapes despite their different compositions ("molecular mimicry"). You will find both EFs by this search. Perform search.

This is a dummy-atom model of lumazine synthase obtained by SAS. You will find many crystal structures of same molecules. Perform search.

Many 70S ribosome structure data are stored in EMDB and PDB. Omokage search is useful to find out such the huge molecule structures. Perform search.

For huger molecule, such as this rice dwarf virus, Omokage search can be used. Perform search.

Not only for the huge structures but also for small molecules, such as this DNA fragment, this tool might be useful. By this search, some proteins having similar shape to this DNA fragment are found (for good or for bad). Perform search.

This is another example for small molecules. Which proteins have simialar shapes to this beta-propeller structure? Perform search.




You can use your original data or a modified data for the search. Select type of the file and upload the file by this form.

Data type:

PDB format coordinate file (atomic model, SAXS bead model, etc)
Uncompressed or gzip-compressed file


3D density map file in CCP4/MRC format (voxels must be cubic)
Max voxel number is ~200. Large map data should be trimmed and shrined before uploading.
Uncompressed or gzip-compressed file is uploadable

Surface level:

Codebook vectors made by qvol or qpdb tool in Situs package. Two models, model with 30 and 50 points are required for Omokage comparison. Documentation is under construction.

30-dot model:
50-dot model:

About Omokage search


Apr 13, 2016. Omokage search got faster

Omokage search got faster

  • The computation time became ~1/2 compared to the previous version by re-optimization of data accession
  • Enjoy "shape similarity" of biomolecules, more!

Related info.: Omokage search

Mar 3, 2016. Presentation (PDF format) at IPR seminar on Feb 19.

Dec 4, 2015. The article about Omokage search is published online

The article about Omokage search is published online

Related info.: Omokage search / gmfit

Nov 28, 2015. Omokage search starts to support SASBDB models

Omokage search starts to support SASBDB models

  • Models data in SASBDB are added to the Omokage search database.
  • SASBDB is a databank for small angle scattering data
  • A SASBDB model can be used as a search query.
  • The search result may include SASBDB models.

Related info.: Omokage search / SASBDB / Comparison of 3 databanks

Sep 22, 2014. New service: Omokage search

New service: Omokage search

  • Shape similarity search service, Omokage search has started.
  • Related info.: Omokage search

    Read more

    Omokage search

    Search structure by SHAPE

    • "Omokage search" is a shape similarity search service for 3D structures of macromolecules. By comparing global shapes, and ignoring details, similar-shaped structures are searched.
    • The search is performed ageinst >200,000 structure data, which consists of EMDB map data, PDB coordinates (deposited units (asymmetric units, usually), PDB biological units, and SASBDB mdoels).
    • For the search query, you can use either a data in the PDB/EMDB/SASBDB or your original model.
    • Supported formats are PDB (atomic model, SAXS bead model, etc.) and CCP4/MRC map (3D density map).
    • Shape comparison is performed by iDR profile method, which uses 1D-distance profiles of super-simplified models generated by vector quantizaion in Situs package.

    Related info.: Comparison of 3 databanks / Sep 22, 2014. New service: Omokage search / gmfit / Re-ranking by gmfit

    Read more