1amp
CRYSTAL STRUCTURE OF AEROMONAS PROTEOLYTICA AMINOPEPTIDASE: A PROTOTYPICAL MEMBER OF THE CO-CATALYTIC ZINC ENZYME FAMILY
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OverviewOverview
BACKGROUND: Aminopeptidases specifically cleave the amino-terminal residue, from polypeptide chains and are involved in the metabolism of biologically, active peptides. The family includes zinc-dependent enzymes possessing, either one or two zinc ions per active site. Structural studies providing, a detailed view of the metal environment may reveal whether the one-zinc, and two-zinc enzymes constitute structurally and mechanistically distinct, subclasses, and what role the metal ions play in the catalytic process., RESULTS: We have solved the crystal structure of the monomeric, aminopeptidase from Aeromonas proteolytica at 1.8 A resolution. The, protein is folded into a single alpha/beta globular domain. The active, site contains two zinc ions (3.5 A apart) with shared ligands and, symmetrical coordination spheres. We have compared it with the related, bovine lens leucine aminopeptidase and the cobalt-containing Escherichia, coli methionine aminopeptidase. CONCLUSIONS: The environment and, coordination of the two zinc ions in A. proteolytica aminopeptidase, strongly support the view that the two metal ions constitute a, co-catalytic unit and play equivalent roles during catalysis. This, conflicts with the conclusions drawn from the related bovine leucine, aminopeptidase and early biochemical studies. In addition, the known, specificity of the aminopeptidase for hydrophobic amino-terminal residues, is reflected in the hydrophobicity of the active site cleft.
About this StructureAbout this Structure
1AMP is a Single protein structure of sequence from Vibrio proteolyticus with ZN as ligand. Active as Bacterial leucyl aminopeptidase, with EC number 3.4.11.10 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of Aeromonas proteolytica aminopeptidase: a prototypical member of the co-catalytic zinc enzyme family., Chevrier B, Schalk C, D'Orchymont H, Rondeau JM, Moras D, Tarnus C, Structure. 1994 Apr 15;2(4):283-91. PMID:8087555
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