1c7k
From Proteopedia
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CRYSTAL STRUCTURE OF THE ZINC PROTEASE
Overview
A zinc endoprotease produced by Streptomyces caespitosus (ScNP) contains a, H83E84TGH87VLG90LPD93-Met103 sequence. Except for D93, this amino acid, sequence is the same as a characteristic consensus HEXXHXXGXXH-M motif, found in one class of zinc endoprotease called 'metzincins'. We analyzed, the structural and functional role of the consensus sequence located, around a catalytically essential zinc ion based on the crystal structure, of ScNP. The structure was determined at the highest level on resolution, (1 A resolution) and accuracy among crystal structures of zinc, endoproteases ever determined. The zinc ion of ScNP is tetrahedrally, coordinated by three amino acid side-chains (H83, H87 and D93) and a water, molecule. The distances between the zinc ion and the coordinating atoms, are 2.01, 2.01 and 1.95 A for H83N epsilon, H87N epsilon and D93O delta, respectively. These distances agree very well with those normally found in, crystal structures of zinc-containing small molecules in the Cambridge, Structural Database. On the other hand, the distance between the zinc ion, and the coordinating water molecule (1.93 A) is slightly shorter than the, typical value (2.01 A) found in the database. In addition, E84O epsilon, makes a short hydrogen bond to this water molecule with the distance of, 2.54 A. Two hydrogen bonds (H83N delta-L102O, H87N delta-L91O) and van der, Waals interactions between the side-chain of M103 and the two imidazole, rings of H83 and H87 are also observed. These interactions are probably, important for the imidazole rings to construct the tetrahedral, coordination arrangement toward the zinc ion.
About this Structure
1C7K is a Single protein structure of sequence from Streptomyces caespitosus with ZN and CA as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structure of the zinc-binding site in the crystal structure of a zinc endoprotease from Streptomyces caespitosus at 1 A resolution., Kurisu G, Kai Y, Harada S, J Inorg Biochem. 2000 Nov;82(1-4):225-8. PMID:11132632
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