The domain within your query sequence starts at position 420 and ends at position 569; the E-value for the RPT_2 domain shown below is 5.58e-9.

GSKQNVEDSTLSTGSATSNEGDDKSSDNSSNTFREDLEKILEQITSAPGGSAERPNAQSS
NNLSGKLEPKYENPTNGSSSASSADKPYEEGMRKLLKFLEEQYGQTGTDASVSGMSSESS
RSNVHLSDGFSMESGDDATVQGQQAAASGG

This is a significant internal repeat in the query protein sequence, as detected by the Prospero program.