This domain is called PHR as it was original found in the proteins PAM, highwire and RPM. This domain can be duplicated in the highwire, PFAM and PRM sequence. The C-terminal region of the protein BTBD1 includes the PHR domain and is known to interact with Topoisomerase I, an enzyme which relaxes DNA supercoils.
Jiyao W et al.(2023). "The conserved domain database in 2023.",