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TagIdent tool (formerly GuessProt)

We apologize for the current unavailability of our TagIdent tool. The ever-increasing amount of data, and the recent format change of sequence annotations (Features) in the UniProtKB text format caused our tools AACompIdent, MultiIdent and TagIdent to no longer work. All three tools were using the same index files which we can no longer maintain.

We do realize that TagIdent is still relatively widely used and are working on bringing it back as an independent tool.

In the meantime, several of the functionalities provided by TagIdent can be obtained on the UniProt website. It is the search by isoelectric point (pI) that is currently not possible.

Here is what you can do on UniProt:

  1. Use the Advanced search functionality to search by protein mass, organism, taxonomy, keyword

    Related UniProt help pages:

  2. Use the PeptideSearch service, to specify short sequence tags.
You can combine both approaches, e.g. to search for all human proteins with masses between 10000 and 50000 Dalton whose sequences match "ANTGR".

To do so, you can first run a PeptideSearch against the organism of your choice, e.g. submit

against Homo sapiens (Human). Here is the list of results:

Then you can add criteria like

mass:[10000 TO 50000]
to the search box and click on Submit. This returns all human proteins that match the sequence ANTGR and have a mass between 10000 and 50000 Dalton:

Note that the job identifiers (such as P202004028BC4D7ADE02784B0C2481C7F3DE0963A004DBC6 are temporary and are only kept for 7 days).

Please don't hesitate to give it a try. If this doesn't work for you, please get back to us and let us know your use case. We hope to have a dedicated replacement for TagIdent up in the next few months.