Amidation of Bioactive Peptides: The Structure of the Lyase Domain of the Amidating Enzyme

Journal Article · Thu Jan 01 00:00:00 EST 2009 · Structure

DOI:https://doi.org/10.1016/j.str.2009.05.008· OSTI ID:980001

Chufan, E; De, M; Eipper, B; Mains, R; Amzel, L

Many neuropeptides and peptide hormones require amidation of their carboxy terminal for full biological activity. The enzyme peptidyl-{alpha}-hydroxyglycine {alpha}-amidating lyase (PAL; EC 4.3.2.5) catalyzes the second and last step of this reaction, N-dealkylation of the peptidyl-{alpha}-hydroxyglycine to generate the {alpha}-amidated peptide and glyoxylate. Here we report the X-ray crystal structure of the PAL catalytic core (PALcc) alone and in complex with the nonpeptidic substrate {alpha}-hydroxyhippuric acid. The structures show that PAL folds as a six-bladed {Beta}-propeller. The active site is formed by a Zn(II) ion coordinated by three histidine residues; the substrate binds to this site with its {alpha}-hydroxyl group coordinated to the Zn(II) ion. The structures also reveal a tyrosine residue (Tyr{sup 654}) at the active site as the catalytic base for hydroxyl deprotonation, an unusual role for tyrosine. A reaction mechanism is proposed based on this structural data and validated by biochemical analysis of site-directed PALcc mutants.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: DE-AC02-98CH10886
• OSTI ID: 980001
• Report Number(s): BNL-92919-2010-JA; TRN: US201015%%1386
• Journal Information: Structure, Vol. 17, Issue 7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
BASES
CRYSTAL STRUCTURE
DATA
ENZYMES
HISTIDINE
IONS
LYASES
MUTANTS
PEPTIDE HORMONES
PEPTIDES
REACTION KINETICS
RESIDUES
SUBSTRATES
TYROSINE
national synchrotron light source