1amp: Difference between revisions

[[Image:1amp.jpg|left|200px]]<br /><applet load="1amp" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1AMP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_proteolyticus Vibrio proteolyticus] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Bacterial_leucyl_aminopeptidase Bacterial leucyl aminopeptidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.11.10 3.4.11.10] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AMP OCA].  

[[Category: Orchymont, H D.]]

[[Category: Rondeau, J M.]]

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