title: Structural insights into the mechanism of intramolecular proteolysis.
abstract: A variety of proteins, including glycosylasparaginase, have recently been found to activate functions by self-catalyzed peptide bond rearrangements from single-chain precursors. Here we present the 1.9 A crystal structures of glycosylasparaginase precursors that are able to autoproteolyze via an N --> O acyl shift. Several conserved residues are aligned around the scissile peptide bond that is in a highly strained trans peptide bond configuration. The structure illustrates how a nucleophilic side chain may attack the scissile peptide bond at the immediate upstream backbone carbonyl and provides an understanding of the structural basis for peptide bond cleavage via an N --> O or N --> S acyl shift that is used by various groups of intramolecular autoprocessing proteins.
authors.affiliation: Department of Biophysics, Boston University School of Medicine, Massachusetts 02118-2526, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Xu
authors.forename: D
authors.initials: D
authors.lastname: Buckley
authors.forename: C
authors.initials: C
authors.lastname: Guan
authors.forename: H C
authors.initials: HC
authors.lastname: Guo
mesh_terms: D001227:Aspartylglucosylaminase / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D005417:Flavobacterium / Q000201:enzymology; D005998:Glycine / Q000378:metabolism; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011485:Protein Binding; D011487:Protein Conformation; D011498:Protein Precursors / Q000378:metabolism*; D017434:Protein Structure, Tertiary
chemical_list: D011498:Protein Precursors; D001227:Aspartylglucosylaminase; D005998:Glycine