PDBsum entry 2op9

Hydrolase

PDB id: 2op9

Contents

Protein chains

302 a.a. *

Ligands

WR1 ×2

Waters ×491

* Residue conservation analysis

PDB id:

2op9

Name:

Hydrolase

Title:

Substrate specificity profiling and identification of a new class of inhibitor for the major protease of the sars coronavirus

Structure:

Replicase polyprotein 1ab (pp1ab, orf1ab) 3c-like proteinase (3cl-pro, 3clp). Chain: a, b. Engineered: yes

Source:

Sars coronavirus. Organism_taxid: 227859. Strain: tor2. Gene: 3clpro. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.80Å R-factor: 0.172 R-free: 0.207

Authors:

C.S.Craik,D.H.Goetz

Key ref:

D.H.Goetz et al. (2007). Substrate specificity profiling and identification of a new class of inhibitor for the major protease of the SARS coronavirus. Biochemistry, 46, 8744-8752. PubMed id: 17605471

Date:

27-Jan-07 Release date: 17-Jul-07

Protein chains

P0C6X7  (R1AB_CVHSA) -  Replicase polyprotein 1ab from Severe acute respiratory syndrome coronavirus

Seq: 7073 a.a.

Struc: 302 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class 2: E.C.2.1.1.- - ?????
• Enzyme class 3: E.C.2.1.1.56 - mRNA (guanine-N(7))-methyltransferase.
• Reaction: a 5'-end (5'-triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L- methionine = a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L-homocysteine
• Enzyme class 4: E.C.2.1.1.57 - methyltransferase cap1.
• Reaction: a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L-methionine = a 5'-end (N(7)-methyl 5'-triphosphoguanosine)- (2'-O-methyl-ribonucleoside) in mRNA + S-adenosyl-L-homocysteine + H⁺
• Enzyme class 5: E.C.2.7.7.48 - RNA-directed Rna polymerase.
• Reaction: RNA(n) + a ribonucleoside 5'-triphosphate = RNA(n+1) + diphosphate
• Enzyme class 6: E.C.2.7.7.50 - mRNA guanylyltransferase.
• Reaction: a 5'-end diphospho-ribonucleoside in mRNA + GTP + H⁺ = a 5'-end (5'-triphosphoguanosine)-ribonucleoside in mRNA + diphosphate
• Enzyme class 7: E.C.3.1.13.- - ?????
• Enzyme class 8: E.C.3.4.19.12 - ubiquitinyl hydrolase 1.
• Reaction: Thiol-dependent hydrolysis of ester, thiolester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal).
• Enzyme class 9: E.C.3.4.22.- - ?????
• Enzyme class 10: E.C.3.4.22.69 - Sars coronavirus main proteinase.
• Enzyme class 11: E.C.3.6.4.12 - Dna helicase.
• Reaction: ATP + H2O = ADP + phosphate + H⁺
• Enzyme class 12: E.C.3.6.4.13 - Rna helicase.
• Reaction: ATP + H2O = ADP + phosphate + H⁺
• Enzyme class 13: E.C.4.6.1.- - ?????

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

Biochemistry 46:8744-8752 (2007)

PubMed id: 17605471

Substrate specificity profiling and identification of a new class of inhibitor for the major protease of the SARS coronavirus.

D.H.Goetz, Y.Choe, E.Hansell, Y.T.Chen, M.McDowell, C.B.Jonsson, W.R.Roush, J.McKerrow, C.S.Craik.

ABSTRACT

Severe acute respiratory syndrome (SARS) is an emerging infectious disease associated with a high rate of mortality. The SARS-associated coronavirus (SARS-CoV) has been identified as the etiological agent of the disease. Although public health procedures have been effective in combating the spread of SARS, concern remains about the possibility of a recurrence. Various approaches are being pursued for the development of efficacious therapeutics. One promising approach is to develop small molecule inhibitors of the essential major polyprotein processing protease 3Clpro. Here we report a complete description of the tetrapeptide substrate specificity of 3Clpro using fully degenerate peptide libraries consisting of all 160,000 possible naturally occurring tetrapeptides. The substrate specificity data show the expected P1-Gln P2-Leu specificity and elucidate a novel preference for P1-His containing substrates equal to the expected preference for P1-Gln. These data were then used to develop optimal substrates for a high-throughput screen of a 2000 compound small-molecule inhibitor library consisting of known cysteine protease inhibitor scaffolds. We also report the 1.8 A X-ray crystal structure of 3Clpro bound to an irreversible inhibitor. This inhibitor, an alpha,beta-epoxyketone, inhibits 3Clpro with a k3/Ki of 0.002 microM(-1) s(-1) in a mode consistent with the substrate specificity data. Finally, we report the successful rational improvement of this scaffold with second generation inhibitors. These data provide the foundation for a rational small-molecule inhibitor design effort based upon the inhibitor scaffold identified, the crystal structure of the complex, and a more complete understanding of P1-P4 substrate specificity.