title: The high-resolution structures of the neutral and the low pH crystals of aminopeptidase from Aeromonas proteolytica.
abstract: The aminopeptidase from Aeromonas proteolytica (AAP) contains two zinc ions in the active site and catalyzes the degradation of peptides. Herein we report the crystal structures of AAP at 0.95-A resolution at neutral pH and at 1.24-A resolution at low pH. The combination of these structures allowed the precise modeling of atomic positions, the identification of the metal bridging oxygen species, and insight into the physical properties of the metal ions. On the basis of these structures, a new putative catalytic mechanism is proposed for AAP that is likely relevant to all binuclear metalloproteases.
authors.affiliation: Program in Biophysics and Structural Biology, Brandeis University, 415 South Street, Waltham, MA 02254-9110, USA.
authors.forename: William
authors.initials: W
authors.lastname: Desmarais
authors.forename: David L
authors.initials: DL
authors.lastname: Bienvenue
authors.forename: Krzysztof P
authors.initials: KP
authors.lastname: Bzymek
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Petsko
authors.forename: Dagmar
authors.initials: D
authors.lastname: Ringe
authors.forename: Richard C
authors.initials: RC
authors.lastname: Holz
mesh_terms: D000333:Aeromonas / Q000201:enzymology* / Q000378:metabolism; D000626:Aminopeptidases / Q000737:chemistry* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D003460:Crystallization; D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D008958:Models, Molecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D015032:Zinc / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D000626:Aminopeptidases; D015032:Zinc