1ns3
From Proteopedia
(New page: 200px<br /><applet load="1ns3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ns3, resolution 2.8Å" /> '''STRUCTURE OF HCV PROT...) |
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| - | [[Image:1ns3.gif|left|200px]]<br /><applet load="1ns3" size=" | + | [[Image:1ns3.gif|left|200px]]<br /><applet load="1ns3" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ns3, resolution 2.8Å" /> | caption="1ns3, resolution 2.8Å" /> | ||
'''STRUCTURE OF HCV PROTEASE (BK STRAIN)'''<br /> | '''STRUCTURE OF HCV PROTEASE (BK STRAIN)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of the NS3 protease of the hepatitis C virus (BK | + | The crystal structure of the NS3 protease of the hepatitis C virus (BK strain) has been determined in the space group P6(3)22 to a resolution of 2.2 A. This protease is bound with a 14-mer peptide representing the central region of the NS4A protein. There are two molecules of the NS3(1-180)-NS4A(21'-34') complex per asymmetric unit. Each displays a familiar chymotrypsin-like fold that includes two beta-barrel domains and four short alpha-helices. The catalytic triad (Ser-139, His-57, and Asp-81) is located in the crevice between the beta-barrel domains. The NS4A peptide forms an almost completely enclosed peptide surface association with the protease. In contrast to the reported H strain complex of NS3 protease-NS4A peptide in a trigonal crystal form (Kim JL et al., 1996, Cell 87:343-355), the N-terminus of the NS3 protease is well-ordered in both molecules in the asymmetric unit of our hexagonal crystal form. The folding of the N-terminal region of the NS3 protease is due to the formation of a three-helix bundle as a result of crystal packing. When compared with the unbound structure (Love RA et al., 1996, Cell 87:331-342), the binding of the NS4A peptide leads to the ordering of the N-terminal 28 residues of the NS3 protease into a beta-strand and an alpha-helix and also causes local rearrangements important for a catalytically favorable conformation at the active site. Our analysis provides experimental support for the proposal that binding of an NS4A-mimicking peptide, which increases catalytic rates, is necessary but not sufficient for formation of a well-ordered, compact and, hence, highly active protease molecule. |
==About this Structure== | ==About this Structure== | ||
| - | 1NS3 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Hepatitis_c_virus Hepatitis c virus] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1NS3 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Hepatitis_c_virus Hepatitis c virus] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NS3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: serine proteinase]] | [[Category: serine proteinase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:09:26 2008'' |
Revision as of 12:09, 21 February 2008
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STRUCTURE OF HCV PROTEASE (BK STRAIN)
Overview
The crystal structure of the NS3 protease of the hepatitis C virus (BK strain) has been determined in the space group P6(3)22 to a resolution of 2.2 A. This protease is bound with a 14-mer peptide representing the central region of the NS4A protein. There are two molecules of the NS3(1-180)-NS4A(21'-34') complex per asymmetric unit. Each displays a familiar chymotrypsin-like fold that includes two beta-barrel domains and four short alpha-helices. The catalytic triad (Ser-139, His-57, and Asp-81) is located in the crevice between the beta-barrel domains. The NS4A peptide forms an almost completely enclosed peptide surface association with the protease. In contrast to the reported H strain complex of NS3 protease-NS4A peptide in a trigonal crystal form (Kim JL et al., 1996, Cell 87:343-355), the N-terminus of the NS3 protease is well-ordered in both molecules in the asymmetric unit of our hexagonal crystal form. The folding of the N-terminal region of the NS3 protease is due to the formation of a three-helix bundle as a result of crystal packing. When compared with the unbound structure (Love RA et al., 1996, Cell 87:331-342), the binding of the NS4A peptide leads to the ordering of the N-terminal 28 residues of the NS3 protease into a beta-strand and an alpha-helix and also causes local rearrangements important for a catalytically favorable conformation at the active site. Our analysis provides experimental support for the proposal that binding of an NS4A-mimicking peptide, which increases catalytic rates, is necessary but not sufficient for formation of a well-ordered, compact and, hence, highly active protease molecule.
About this Structure
1NS3 is a Protein complex structure of sequences from Hepatitis c virus with as ligand. Full crystallographic information is available from OCA.
Reference
Complex of NS3 protease and NS4A peptide of BK strain hepatitis C virus: a 2.2 A resolution structure in a hexagonal crystal form., Yan Y, Li Y, Munshi S, Sardana V, Cole JL, Sardana M, Steinkuehler C, Tomei L, De Francesco R, Kuo LC, Chen Z, Protein Sci. 1998 Apr;7(4):837-47. PMID:9568891
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