PAL catalyzes the N-dealkylation of peptidyl-alpha-hydroxyglycine, which results in an alpha-amidated peptide and glyoxylate. Amidation of the C-terminus is required for the activity of many peptide hormones and neuropeptides. The catalytic residues of PAL are located on several NHL-repeats. The NHL (NCL-1, HT2A and LIN-41) repeat is found in multiple tandem copies, typically as 6 instances. It is about 40 residues long and resembles the WD repeat and other beta-propeller structures.
Feature 1: active site [active site], 7 residue positions
Conserved feature residue pattern:H x Y x H R H
Evidence:
Comment:A disulfide bridge is conserved in many members of the PAL family and serves a structural role in anchoring the active-site tyrosine, which deprotonates the substrate alpha-hydroxy group
Structure:3FVZ: Rattus norvegicus PAL binds zinc and an acetate ion; contacts at 4.0A
Structure:3FW0: Rattus norvegicus PAL binds the non-peptidic substrate alpha-hydroxyhippuric acid and a mercury (II) ion; contacts at 4.0A
Jiyao W et al.(2023). "The conserved domain database in 2023.",