Involved in prephenate-dependent formation of 5-hydroxyuridine (ho5U) modification at position 34 in tRNAs, the first step in 5-methoxyuridine (mo5U) biosynthesis. Deletion mutant lacking both trhP1 and trhP2 shows reduced 5-methoxyuridine (mo5U) formation in tRNAs. Belongs to the peptidase U32 family.