6w79

X-ray diffraction
1.46Å resolution

Structure of SARS-CoV main protease bound to potent broad-spectrum non-covalent inhibitor X77

Released:
Entry authors: Mesecar AD, StJohn S, Center for Structural Genomics of Infectious Diseases (CSGID)

Function and Biology Details

Reactions catalysed:
Nucleoside triphosphate + RNA(n) = diphosphate + RNA(n+1)
ATP + H(2)O = ADP + phosphate
Thiol-dependent hydrolysis of ester, thioester, 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).
S-adenosyl-L-methionine + a 5'-(N(7)-methyl 5'-triphosphoguanosine)-(ribonucleotide)-[mRNA] = S-adenosyl-L-homocysteine + a 5'-(N(7)-methyl 5'-triphosphoguanosine)-(2'-O-methyl-ribonucleotide)-[mRNA]
TSAVLQ-|-SGFRK-NH(2) and SGVTFQ-|-GKFKK the two peptides corresponding to the two self-cleavage sites of the SARS 3C-like proteinase are the two most reactive peptide substrates. The enzyme exhibits a strong preference for substrates containing Gln at P1 position and Leu at P2 position.
Biochemical function:
  • not assigned
Biological process:
  • not assigned
Cellular component:
  • not assigned

Structure analysis Details

Assembly composition:
homo dimer (preferred)
Entry contents:
1 distinct polypeptide molecule
Macromolecule:
3C-like proteinase nsp5 Chain: A
Molecule details ›
Chain: A
Length: 306 amino acids
Theoretical weight: 33.88 KDa
Source organism: Severe acute respiratory syndrome coronavirus 2
Expression system: Escherichia coli BL21(DE3)
UniProt:
  • Canonical: P0C6X7 (Residues: 3241-3546; Coverage: 4%)
Gene names: 1a-1b, rep

Ligands and Environments

3 bound ligands:
No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: APS BEAMLINE 21-ID-G
Spacegroup: C2
Unit cell:
a: 108.881Å b: 81.26Å c: 53.455Å
α: 90° β: 104.231° γ: 90°
R-values:
R R work R free
0.157 0.156 0.177
Expression system: Escherichia coli BL21(DE3)