1Z1J

Crystal structure of SARS 3CLpro C145A mutant

Summary for 1Z1J

• Entry DOI: 10.2210/pdb1z1j/pdb
• Related: 1Z1I
• Descriptor: 3C-like proteinase (2 entities in total)
• Functional Keywords: hydrolase
• Biological source: SARS coronavirus
• Cellular location: Non-structural protein 3: Host membrane; Multi-pass membrane protein (Potential). Non-structural protein 4: Host membrane; Multi-pass membrane protein (Potential). Non-structural protein 6: Host membrane; Multi-pass membrane protein (Potential). Non-structural protein 7: Host cytoplasm, host perinuclear region (By similarity). Non-structural protein 8: Host cytoplasm, host perinuclear region (By similarity). Non-structural protein 9: Host cytoplasm, host perinuclear region (By similarity). Non-structural protein 10: Host cytoplasm, host perinuclear region (By similarity). Helicase: Host endoplasmic reticulum-Golgi intermediate compartment (Potential). Uridylate-specific endoribonuclease: Host cytoplasm, host perinuclear region (By similarity): P59641
• Total number of polymer chains: 2
• Total formula weight: 67689.14

Authors

Hsu, M.F. (deposition date: 2005-03-04, release date: 2005-11-22, Last modification date: 2024-05-29)

Primary citation

Hsu, M.F.,Kuo, C.J.,Fang, J.M.,Shie, J.J.,Chang, K.T.,Chang, H.C.,Chou, C.C.,Ko, T.P.,Shr, H.L.,Chang, G.G.,Wu, Y.T.,Wang, A.H.,Liang, P.H.
Understanding the maturation process and inhibitor design of SARS-CoV 3CLpro from the crystal structure of C145A in a product-bound form
J.Biol.Chem., 280:31257-31266, 2005

PubMed Abstract: Severe acute respiratory syndrome (SARS) is an emerging infectious disease caused by a novel human coronavirus. Viral maturation requires a main protease (3CL(pro)) to cleave the virus-encoded polyproteins. We report here that the 3CL(pro) containing additional N- and/or C-terminal segments of the polyprotein sequences undergoes autoprocessing and yields the mature protease in vitro. The dimeric three-dimensional structure of the C145A mutant protease shows that the active site of one protomer binds with the C-terminal six amino acids of the protomer from another asymmetric unit, mimicking the product-bound form and suggesting a possible mechanism for maturation. The P1 pocket of the active site binds the Gln side chain specifically, and the P2 and P4 sites are clustered together to accommodate large hydrophobic side chains. The tagged C145A mutant protein served as a substrate for the wild-type protease, and the N terminus was first digested (55-fold faster) at the Gln(-1)-Ser1 site followed by the C-terminal cleavage at the Gln306-Gly307 site. Analytical ultracentrifuge of the quaternary structures of the tagged and mature proteases reveals the remarkably tighter dimer formation for the mature enzyme (K(d) = 0.35 nm) than for the mutant (C145A) containing 10 extra N-terminal (K(d) = 17.2 nM) or C-terminal amino acids (K(d) = 5.6 nM). The data indicate that immature 3CL(pro) can form dimer enabling it to undergo autoprocessing to yield the mature enzyme, which further serves as a seed for facilitated maturation. Taken together, this study provides insights into the maturation process of the SARS 3CL(pro) from the polyprotein and design of new structure-based inhibitors.

PubMed: 15788388
DOI: 10.1074/jbc.M502577200

Experimental method

X-RAY DIFFRACTION (2.8 Å)