Happy Holidays and New year from the EMDB! Please be advised that the EMDB team will be operating at reduced capacity between December 15th - January 12th. With this in mind we would ask that you be prepared for longer reply times through both our helpdesk system and the OneDep deposition system. well done on a productive 2025, wishing you all the best and we will see you in 2026!

FAQ

EM map deposition questions

EM map-derived coordinate model deposition questions

EM map, model and metadata access questions

EM map deposition answers

How do I begin a map deposition to EMDB?

EMDB maps can be deposited through the wwPDB OneDep system. Tutorials for which can be found here.

What map formats are accepted by EMDB?

Maps can be deposited in mrc and ccp4 formats; they are converted to standard ccp4 format for redistribution in the EMDB.

What is the difference between a deposition session id and an EMDB accession id ?

When you initiate a deposition session you are assigned a session id (reference code). The session id is a "private" identifier known only to the depositor and the deposition site. When you complete your deposition and submit it to the EMDB, you are assigned a public accession code ("EMD-" followed by a four or five digit number). The public accession code is the id you should provide to journals when indicating your EMDB submission; it is also the code by which you can access to your entry in the publicly available EMDB search and atlas pages.

We have two maps for one submitted manuscript, one native, one with cofactor protein. Do we need to complete two separate depositions?

If the maps were generated from different specimen preparations/imaging experiments you will need to make two separate depositions.
Time saving tip: complete the submission for the first map (deposition session 1), and then for the second map (deposition session 2) select the option "based on previous submission." You will need to provide the 1st deposition session id and password in order to use this option.

Can I deposit a composite map to EMDB?

A composite map is here defined as a map constructed by piecing together two or more experimentally derived component EM maps together. A composite map may be deposited to EMDB if the component maps share the same specimen preparations/imaging experiments (see also "We have two maps for one submitted manuscript, one native, one with cofactor protein. Do we need to complete two separate depositions?”). For composite map depositions we ask that you: a) also provide each of the component maps as individual EMDB entries, in addition to the composite map entry; b) add the following suffix to the composite map entry title: “(composite structure).”

How can we deposit multiple 3D volumes generated from imaging of a single specimen?

EM reconstruction methods are beginning to yield ensembles of maps representing multiple conformations/enzymatic states within a heterogeneous population of imaged particles. If you need to deposit multiple maps of this type you can do so either within a single submission, in which case one map must be designated at the primary map, or a separate submissions (please see answer above).

How can I request a change/correction/citation update to my EMDB entry?

Please log into your OneDep deposition and make the request using the communication module.

Our manuscript has not been officially accepted yet, so please do not release our entry.

The only part of an EMDB submission that is released immediately is the experimental information in the header. The header information will only be released after you have had an opportunity to comment on the curated data. The map will not be released until the hold period has elapsed which can be on publication (HPUB), or 1 year from deposition. The map will only be released immediately if you have requested this at the release option stage.

I received an email stating that my map is being released. When will it be available in the EM Data Bank?

EMDB follows the same weekly release cycle as PDB. Maps queued for release before Thursday at 5pm (UK) will be available from EMDB on the following Wednesday.

The journal I am targeting requires editors and referees access to the structure while my manuscript is under review. Does EMDB provide confidential access to editors or referees if a structure is "on hold"?

Unreleased structural data on hold, both maps and coordinate sets, are kept strictly confidential. After deposition, you will immediately receive EMDB ids for your map entries and PDB ids for your map-derived model entries, which you may include in your manuscript. In addition, for PDB model entries you can obtain validation reports that provide assessments of model quality while keeping the coordinate file confidential. We encourage journal editors and referees to request validation reports from depositors as part of the manuscript submission and review process. The reports are date-stamped, and display the wwPDB processing site logo. For more information see https://www.wwpdb.org/validation.html.

EM map-derived coordinate model deposition answers

I have fitted coordinates for my map, can I include them with my map entry?

Fitted coordinate models for EM entries may be deposited along with your map; they will be assigned a PDB id.

I obtained coordinates from PDB and used rigid-body fitting to place them into my map. Can I deposit these coordinates to PDB?

You can deposit coordinates derived from any fitting protocol, including rigid-body fitting, flexible fitting, or de novo tracing. The deposited coordinates must be aligned and in-frame with the map.

My fitted coordinates correspond to a protein homolog. During the PDB deposition, should I provide the species information/sequence information for the EM sample or for the protein homolog?

The species information should correspond to your EM sample, but the sequence information should correspond to the protein homolog/fitted model.

How are coordinates derived from EM reconstructions validated?

Currently, model fit to an EMDB map is validated through visual inspection of the deposited map + model pair using a 3D graphics program. Models are also checked for correct stereochemistry and clashes; a validation report is issued for every submitted model.

We have a new coordinate model fitted into an EMDB map entry authored by another research group. Can we deposit our coordinates?

Yes, you can deposit your coordinates. Provide the EMDB map accession id (EMD-XXXX) as the associated EM volume of your coordinate deposition. The PDB policy regarding re-refined entries applies: "A re-refined entry may be deposited prior to publication but will not be processed (will have REFI status) or released until the associated publication has become publicly available." No changes will be made to the EMDB map entry.

EM map, model and metadata access answers

How can I find/download a map or browse the EMDB archive?

You can use the advanced search link on the top of the page.

How can I view EMDB maps?

To view the map on your own computer, you will first need to download the map from the EMDB atlas page and view the map with locally installed software. ChimeraX, Pymol, Coot (v. 0.6.2 or later), and other graphics programs can display EMDB maps when loaded as "ccp4" format maps.

How can I download a map that has already been deposited and released?

Released maps can be downloaded either from the 'downloads' tab of the atlas page for the entry or from one of the three wwPDB ftp distribution sites: ftp://ftp.ebi.ac.uk/pub/databases/emdb, https://ftp.wwpdb.org/pub/emdb or https://data.pdbj.org/pub/emdb. Some strategies to retrieve files from the ftp sites are posted here: https://www.wwpdb.org/download/downloads.php

Can I use maps and/or map images from EMDB in my thesis/publication?

Data files contained in the EMDB are free of all copyright restrictions and made fully and freely available for both non-commercial and commercial use. Users of the data should attribute the original authors of the structural data and the EMDB accession id. Many of the static EM map images shown on atlas pages have been contributed by the original deposition authors in which case they may also be protected by copyright law, even though we provide free access to them. The respective copyright holders of author-provided images retain rights for reproduction, redistribution and reuse. Users are responsible for compliance with copyright restrictions and are expected to adhere to the terms and conditions defined by the copyright holder.

How can I download EMDB map entry metadata?

The EMDB is distributed as a branch of the wwPDB archive, and is available via all of the wwPDB ftp sites. Instructions to retrieve EMDB xml metadata files are posted here: https://www.wwpdb.org/download/downloads.php