The domain within your query sequence starts at position 390 and ends at position 506; the E-value for the RPT_1 domain shown below is 1.75e-17.

SEYFLSENIPFQDNQSQDTPSQYTPSQDIQFQDMLAQDISFQEIQSQESPNQDVLYQETP
PQETPSQGTPYQDLPYQVLLIKDTSPQGTPYQYILTKEIPFQETPSQGTLSQESPSQ

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