The domain within your query sequence starts at position 510 and ends at position 703; the E-value for the RPT_1 domain shown below is 1.39e-9.

SGDSQPQVNLFSSTKNIMSVQNNGTQQQGNSLFQQGSEMMSLQSGNFLQQSSHSQAQLFH
PQNPIADAQNLSQETQGSIFHSPNPIVHSQTSTASSEQLQPSMFHSQNTIAVLQGSSVPQ
DQQSPNIFLSQSSINNLQTNTVAQEEQISFFAAQNSISPLQSTSNTEQQAAFQQQPPISH
IQTPILSQEQAQPS

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