The domain within your query sequence starts at position 427 and ends at position 491; the E-value for the RPT_3 domain shown below is 7.39e-12.

RGPSGEPGKNGAKGEPGARGERGEAGSPGIPGPKGEDGKDGSPGEPGANGLPGAAGERGP
SGFRG

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