3FAN

Crystal structure of chymotrypsin-like protease/proteinase (3CLSP/Nsp4) of porcine reproductive and respiratory syndrome virus (PRRSV)

3FAN の概要

• エントリーDOI: 10.2210/pdb3fan/pdb
• 関連するPDBエントリー: 1MBM 3FAO
• 分子名称: Non-structural protein, PHOSPHATE ION (3 entities in total)
• 機能のキーワード: chymotrypsin-like, n-terminal beta-barrels, c-terminal alpha-beta extra domain, canonical catalytic triad, hydrolase
• 由来する生物種: Porcine respiratory and reproductive syndrome virus (PRRSV)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 22096.87

構造登録者

Gao, F.,Peng, H.,Tian, X.,Lu, G.,Liu, Y.,Gao, G.F. (登録日: 2008-11-17, 公開日: 2009-09-08, 最終更新日: 2023-12-27)

主引用文献

Tian, X.,Lu, G.,Gao, F.,Peng, H.,Feng, Y.,Ma, G.,Bartlam, M.,Tian, K.,Yan, J.,Hilgenfeld, R.,Gao, G.F.
Structure and cleavage specificity of the chymotrypsin-like serine protease (3CLSP/nsp4) of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV).
J.Mol.Biol., 392:977-993, 2009

PubMed Abstract: Biogenesis and replication of the porcine reproductive and respiratory syndrome virus (PRRSV) include the crucial step of replicative polyprotein processing by self-encoded proteases. Whole genome bioinformatics analysis suggests that nonstructural protein 4 (nsp4) is a 3C-like serine protease (3CLSP), responsible for most of the nonstructural protein processing. The gene encoding this protease was cloned and expressed in Escherichia coli in order to confirm this prediction. The purified protein was crystallized, and the structure was solved at 1.9 A resolution. In addition, the crystal structure of the Ser118Ala mutant was determined at 2.0 A resolution. The monomeric enzyme folds into three domains, similar to that of the homologous protease of equine arteritis virus, which, like PRRSV, is a member of the family Arteriviridae in the order of Nidovirales. The active site of the PRRSV 3CLSP is located between domains I and II and harbors a canonical catalytic triad comprising Ser118, His39, and Asp64. The structure also shows an atypical oxyanion hole and a partially collapsed S1 specificity pocket. The proteolytic activity of the purified protein was assessed in vitro. Three sites joining nonstructural protein domains in the PRRSV replicative polyprotein are confirmed to be processed by the enzyme. Two of them, the nsp3/nsp4 and nsp11/nsp12 junctions, are shown to be cleaved in trans, while cis cleavage is demonstrated for the nsp4/nsp5 linker. Thus, we provide structural evidence as well as enzymatic proof of the nsp4 protein being a functional 3CLSP. We also show that the enzyme has a strong preference for glutamic acid at the P1 position of the substrate.

PubMed: 19646449
DOI: 10.1016/j.jmb.2009.07.062

実験手法

X-RAY DIFFRACTION (1.9 Å)