The domain within your query sequence starts at position 427 and ends at position 488; the E-value for the RPT_1 domain shown below is 1.9e-17.

RGPSGEPGKNGAKGEPGARGERGEAGSPGIPGPKGEDGKDGSPGEPGANGLPGAAGERGP
SG

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