The crystal structure of prolyl aminopeptidase complexed with Sar-TBODA (1X2B) and Ala-Tboda (1X2E) reveal unusual extra space at the active site and high activity for acetylated hydroxyproline. Published by Nakajima et al.. Three new families of proteins of unknown function were created: Duf_452 all bacteria, Duf_818 Chlamydia and Parachlamydia proteins, Duf_1749 plant and fungal Mutations to create dissulfide bonds and increase stability in drome-ACHE published by Ranaei-Siadat et al.