The domain within your query sequence starts at position 1819 and ends at position 1881; the E-value for the RPT_3 domain shown below is 1.48e-5.

PSSSLPKRTREEEEDSTMEAGDQVSEDTVEMPLPKKLKMVTPVGTEEEVMAEESTDGEAE
TQA

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