title: Characterization of member of DUF1888 protein family, self-cleaving and self-assembling endopeptidase.
abstract: The crystal structure of SO1698 protein from Shewanella oneidensis was determined by a SAD method and refined to 1.57 Å. The structure is a β sandwich that unexpectedly consists of two polypeptides; the N-terminal fragment includes residues 1-116, and the C-terminal one includes residues 117-125. Electron density also displayed the Lys-98 side chain covalently linked to Asp-116. The putative active site residues involved in self-cleavage were identified; point mutants were produced and characterized structurally and in a biochemical assay. Numerical simulations utilizing molecular dynamics and hybrid quantum/classical calculations suggest a mechanism involving activation of a water molecule coordinated by a catalytic aspartic acid.
authors.affiliation: Midwest Center for Structural Genomics and Structural Biology Center, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Osipiuk
authors.forename: Rory
authors.initials: R
authors.lastname: Mulligan
authors.forename: Monireh
authors.initials: M
authors.lastname: Bargassa
authors.forename: John E
authors.initials: JE
authors.lastname: Hamilton
authors.forename: Mark A
authors.initials: MA
authors.lastname: Cunningham
authors.forename: Andrzej
authors.initials: A
authors.lastname: Joachimiak
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D010450:Endopeptidases / Q000737:chemistry* / Q000378:metabolism; D020592:Shewanella / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D010450:Endopeptidases