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1iad
From Proteopedia
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|SITE= | |SITE= | ||
|LIGAND= | |LIGAND= | ||
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Astacin Astacin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.24.21 3.4.24.21] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Astacin Astacin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.24.21 3.4.24.21] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1iad FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1iad OCA], [http://www.ebi.ac.uk/pdbsum/1iad PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1iad RCSB]</span> | ||
}} | }} | ||
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[[Category: zinc endopeptidase]] | [[Category: zinc endopeptidase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:16:54 2008'' |
Revision as of 18:16, 30 March 2008
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| , resolution 2.3Å | |||||||
|---|---|---|---|---|---|---|---|
| Activity: | Astacin, with EC number 3.4.24.21 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
REFINED 1.8 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF ASTACIN, A ZINC-ENDOPEPTIDASE FROM THE CRAYFISH ASTACUS ASTACUS L. STRUCTURE DETERMINATION, REFINEMENT, MOLECULAR STRUCTURE AND COMPARISON TO THERMOLYSIN
Overview
Astacin, a 200 residue digestive zinc-endopeptidase from the crayfish Astacus astacus L., is the prototype of the "astacin family", which comprises several membrane-bound mammalian endopeptidases and developmentally implicated regulatory proteins. Large trigonal crystals of astacin were grown, and X-ray reflection data to 1.8 A resolution were collected. The astacin structure has been solved by multiple isomorphous replacement using six heavy-atom derivatives, and refined to a crystallographic R-value of 0.158 applying stringent constraints. All 200 residues are clearly defined by electron density; 181 solvent molecules have been localized. Besides the native structure, the structures of Hg-astacin (with a mercury ion replacing the zinc) and of the apoenzyme were also refined. The astacin molecule exhibits a kidney-like shape. It consists of an amino-terminal and a carboxy-terminal domain, with a deep active-site cleft in between. The zinc ion, located at the bottom of this cleft, is co-ordinated in a novel trigonal-bipyramidal geometry by three histidine residues, a tyrosine and by a water molecule, which is also bound to the carboxylate side-chain of Glu93. The amino-terminal domain of astacin consists mainly of two long alpha-helices, one centrally located and one more peripheral, and of a five-stranded pleated beta-sheet. The amino terminus protrudes into an internal, water-filled cavity of the lower domain and forms a buried salt bridge with Glu103; amino-terminally extended pro-forms of astacin are thus not compatible with this structure. The carboxy-terminal domain of astacin is mainly organized in several turns and irregular structures. Because they share sequence identity of about 35%, the structures of the proteolytic domains of the other "astacin" members must be quite similar to astacin. Only a few very short deletions and insertions quite distant from the active-site distinguish their structures from astacin. The five-stranded beta-sheet and the two helices of the amino-terminal domain of astacin are topologically similar to the structure observed in the archetypal zinc-endopeptidase thermolysin; the rest of the structures are, in contrast, completely unrelated in astacin and thermolysin. The zinc ion, the central alpha-helix and the zinc-liganding residues His92, Glu93 and His96 of astacin are nearly superimposable with the respective groups of thermolysin, namely with the zinc ion, the "active-site helix", and His142TL, Glu143TL and His146TL of the zinc-binding consensus motif His-Glu-Xaa-Xaa-His (where Xaa is any amino acid residue).(ABSTRACT TRUNCATED AT 400 WORDS)
About this Structure
1IAD is a Single protein structure of sequence from Astacus astacus. Full crystallographic information is available from OCA.
Reference
Refined 1.8 A X-ray crystal structure of astacin, a zinc-endopeptidase from the crayfish Astacus astacus L. Structure determination, refinement, molecular structure and comparison with thermolysin., Gomis-Ruth FX, Stocker W, Huber R, Zwilling R, Bode W, J Mol Biol. 1993 Feb 20;229(4):945-68. PMID:8445658
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