The domain within your query sequence starts at position 303 and ends at position 353; the E-value for the RPT_3 domain shown below is 1.87e-6.

GPPGTKGNQGPSGPQGPLGYPGPRGVKGVDGIRGLKGHKGEKGEDGFPGFK

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