2a4o
From Proteopedia
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| - | [[Image:2a4o.gif|left|200px]] | + | [[Image:2a4o.gif|left|200px]] |
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| - | '''Dual modes of modification of Hepatitis A virus 3C protease by a serine derived beta-lactone: selective crytstallization and high resolution structure of the His102 adduct''' | + | {{Structure |
| + | |PDB= 2a4o |SIZE=350|CAPTION= <scene name='initialview01'>2a4o</scene>, resolution 1.55Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=BBL:N-[(BENZYLOXY)CARBONYL]-L-ALANINE'>BBL</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Picornain_3C Picornain 3C], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.22.28 3.4.22.28] | ||
| + | |GENE= 3C ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=12092 Hepatitis A virus]) | ||
| + | }} | ||
| + | |||
| + | '''Dual modes of modification of Hepatitis A virus 3C protease by a serine derived beta-lactone: selective crytstallization and high resolution structure of the His102 adduct''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 2A4O is a [ | + | 2A4O is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Hepatitis_a_virus Hepatitis a virus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A4O OCA]. |
==Reference== | ==Reference== | ||
| - | Dual modes of modification of hepatitis A virus 3C protease by a serine-derived beta-lactone: selective crystallization and formation of a functional catalytic triad in the active site., Yin J, Bergmann EM, Cherney MM, Lall MS, Jain RP, Vederas JC, James MN, J Mol Biol. 2005 Dec 9;354(4):854-71. Epub 2005 Oct 14. PMID:[http:// | + | Dual modes of modification of hepatitis A virus 3C protease by a serine-derived beta-lactone: selective crystallization and formation of a functional catalytic triad in the active site., Yin J, Bergmann EM, Cherney MM, Lall MS, Jain RP, Vederas JC, James MN, J Mol Biol. 2005 Dec 9;354(4):854-71. Epub 2005 Oct 14. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16288920 16288920] |
[[Category: Hepatitis a virus]] | [[Category: Hepatitis a virus]] | ||
[[Category: Picornain 3C]] | [[Category: Picornain 3C]] | ||
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[[Category: beta barrel]] | [[Category: beta barrel]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:45:29 2008'' |
Revision as of 13:45, 20 March 2008
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| , resolution 1.55Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | 3C (Hepatitis A virus) | ||||||
| Activity: | Picornain 3C, with EC number 3.4.22.28 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Dual modes of modification of Hepatitis A virus 3C protease by a serine derived beta-lactone: selective crytstallization and high resolution structure of the His102 adduct
Overview
Hepatitis A virus (HAV) 3C proteinase is a member of the picornain cysteine proteases responsible for the processing of the viral polyprotein, a function essential for viral maturation and infectivity. This and its structural similarity to other 3C and 3C-like proteases make it an attractive target for the development of antiviral drugs. Previous solution NMR studies have shown that a Cys24Ser (C24S) variant of HAV 3C protein, which displays catalytic properties indistinguishable from the native enzyme, is irreversibly inactivated by N-benzyloxycarbonyl-l-serine-beta-lactone (1a) through alkylation of the sulfur atom at the active site Cys172. However, crystallization of an enzyme-inhibitor adduct from the reaction mixture followed by X-ray structural analysis shows only covalent modification of the epsilon2-nitrogen of the surface His102 by the beta-lactone with no reaction at Cys172. Re-examination of the heteronuclear multiple quantum coherence (HMQC) NMR spectra of the enzyme-inhibitor mixture indicates that dual modes of single covalent modification occur with a >/=3:1 ratio of S-alkylation of Cys172 to N-alkylation of His102. The latter product crystallizes readily, probably due to the interaction between the phenyl ring of the N-benzyloxycarbonyl (N-Cbz) moiety and a hydrophobic pocket of a neighboring protein molecule in the crystal. Furthermore, significant structural changes are observed in the active site of the 3C protease, which lead to the formation of a functional catalytic triad with Asp84 accepting one hydrogen bond from His44. Although the 3C protease modified at Cys172 is catalytically inactive, the singly modified His102 N(epsilon2)-alkylated protein displays a significant level of enzymatic activity, which can be further modified/inhibited by N-iodoacetyl-valine-phenylalanine-amide (IVF) (in solution and in crystal) or excessive amount of the same beta-lactone inhibitor (in solution). The success of soaking IVF into HAV 3C-1a crystals demonstrates the usefulness of this new crystal form in the study of enzyme-inhibitor interactions in the proteolytic active site.
About this Structure
2A4O is a Single protein structure of sequence from Hepatitis a virus. Full crystallographic information is available from OCA.
Reference
Dual modes of modification of hepatitis A virus 3C protease by a serine-derived beta-lactone: selective crystallization and formation of a functional catalytic triad in the active site., Yin J, Bergmann EM, Cherney MM, Lall MS, Jain RP, Vederas JC, James MN, J Mol Biol. 2005 Dec 9;354(4):854-71. Epub 2005 Oct 14. PMID:16288920
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