A user recently asked us why two highly similar sequences that contain a PAS domain are in different Pfam families within the PAS clan. The PAS domain clan (CL0183) currently contains seven different families: PAS, PAS_2, PAS_3, etc up to PAS_6, as well as the MEKHLA family. We thought we would take the opportunity to explain some of the rationale behind the way in which we construct and name our families and clans. Read the rest of this entry »