The first step to find out the distribution of your protein of interest is to identify the OG group to which it belongs. We can do this by searching for the protein against the Spirochaetes database.

Here, you can perform a BLAST search for your protein of interest using two databases:

• The SpiroREF database includes all proteins from the reference proteomes of Spirochaetes , ensuring you find all matching hits, though it may return many results from different orthologous groups (OGs). Usually, the first result would be the best match, but you will need to check the statistics presented after the search (e-value, for example)
• The SpiroREP database, on the other hand, contains just one representative sequence per OG, helping you identify the OG your sequence belongs to, but it may not yield high identity matches. In this case, you will usually see a great difference between the best match and all the other hits by checking the statistics presented after the search (e-value, for example).

If in doubt of which database to use, we advise you to use SpiroREP for a first search and, only if you find very similar statistics between two different OGs, you can confirm by searching with SpiroREF. Please note that for a protein to be part of an OG, it must be present in at least two reference proteomes, so SpiroREP may not return significant hits for poorly conserved proteins. To learn more about how the reference genomes were chosen, see the study by Huete SG et al. 2025 . To learn more about how BLAST works, check here .