7xax

X-ray diffraction
2.25Å resolution

Crystal structure of SARS coronavirus main protease in complex with Baicalei

Released:
Primary publication:
Crystal structure of SARS-CoV 3C-like protease with baicalein.
Biochem Biophys Res Commun 611 190-194 (2022)
PMID: 35490659

Function and Biology Details

Reactions catalysed:
S-adenosyl-L-methionine + a 5'-(5'-triphosphoguanosine)-[mRNA] = S-adenosyl-L-homocysteine + a 5'-(N(7)-methyl 5'-triphosphoguanosine)-[mRNA]
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]
Nucleoside triphosphate + RNA(n) = diphosphate + RNA(n+1)
GTP + a 5'-diphospho-[mRNA] = diphosphate + a 5'-(5'-triphosphoguanosine)-[mRNA]
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).
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.
ATP + H(2)O = ADP + phosphate
Biochemical function:
Biological process:
Cellular component:
  • not assigned

Structure analysis Details

Assembly composition:
homo dimer (preferred)
Assembly name:
PDBe Complex ID:
PDB-CPX-143111 (preferred)
Entry contents:
1 distinct polypeptide molecule
Macromolecule:
3C-like proteinase nsp5 Chains: A, B
Molecule details ›
Chains: A, B
Length: 306 amino acids
Theoretical weight: 33.88 KDa
Source organism: Severe acute respiratory syndrome-related coronavirus
Expression system: Escherichia coli BL21(DE3)
UniProt:
  • Canonical: P0C6X7 (Residues: 3241-3546; Coverage: 4%)
Gene names: 1a-1b, rep
Sequence domains: Coronavirus endopeptidase C30

Ligands and Environments

1 bound ligand:
No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: SSRF BEAMLINE BL02U1
Spacegroup: P1
Unit cell:
a: 55.51Å b: 60.55Å c: 68.28Å
α: 90.951° β: 102.715° γ: 108.649°
R-values:
R R work R free
0.232 0.229 0.28
Expression system: Escherichia coli BL21(DE3)