Number and identification of structural domains in protein sequences
For each analyzed record, the values of the number of S1 domains corresponding to the SMART database (about 1200 domains) were selected22. If there was no data on the number of domains in one of the analyzed databases (None), this number was taken equal to zero (these records were deleted from the analyzed dataset). The exact boundaries for each S1 domain for each record were taken from the UniProt database (position, domain, and field of repeats)23.