Structural highlights
Function
R1AB_AMV79 Cysteine protease responsible for the majority of cleavages of the polyprotein (PubMed:25231310, PubMed:26977900). Recognizes substrates containing the core sequence [NT]-[EHKQSY]-|-[AGNST] (PubMed:25231310).[1] [2] The helicase which contains a zinc finger structure displays RNA and DNA duplex-unwinding activities with 5' to 3' polarity. RNA-directed RNA polymerase that catalyzes the transcription of viral genomic and subgenomic RNAs.[UniProtKB:P0DTD1] Catalyzes the RNA N7-guanylyltransferase reaction to methylate the core cap structure GpppN-RNA into the type-0 cap (m)GpppN-RNA.[UniProtKB:Q008X6]
Publication Abstract from PubMed
Cavally virus (CavV) is a mosquito-borne plus-strand RNA virus in the family Mesoniviridae (order Nidovirales). We present X-ray structures for the CavV 3C-like protease (3CL(pro)), as a free enzyme and in complex with a peptide aldehyde inhibitor mimicking the P4-to-P1 residues of a natural substrate. The 3CL(pro) structure (refined to 1.94A) shows that the protein forms dimers. The monomers are comprised of N-terminal domains I and II, which adopt a chymotrypsin-like fold, and a C-terminal alpha-helical domain III. The catalytic Cys-His dyad is assisted by a complex network of interactions involving a water molecule that mediates polar contacts between the catalytic His and a conserved Asp located in the domain II-III junction and is suitably positioned to stabilize the developing positive charge of the catalytic His in the transition state during catalysis. The study also reveals the structural basis for the distinct P2 Asn-specific substrate-binding pocket of mesonivirus 3CL(pro)s.
Structural basis for catalysis and substrate specificity of a 3C-like cysteine protease from a mosquito mesonivirus.,Kanitz M, Blanck S, Heine A, Gulyaeva AA, Gorbalenya AE, Ziebuhr J, Diederich WE Virology. 2019 May 2;533:21-33. doi: 10.1016/j.virol.2019.05.001. PMID:31078932[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Blanck S, Stinn A, Tsiklauri L, Zirkel F, Junglen S, Ziebuhr J. Characterization of an alphamesonivirus 3C-like protease defines a special group of nidovirus main proteases. J Virol. 2014 Dec;88(23):13747-58. PMID:25231310 doi:10.1128/JVI.02040-14
- ↑ Blanck S, Ziebuhr J. Proteolytic processing of mesonivirus replicase polyproteins by the viral 3C-like protease. J Gen Virol. 2016 Jun;97(6):1439-1445. PMID:26977900 doi:10.1099/jgv.0.000458
- ↑ Kanitz M, Blanck S, Heine A, Gulyaeva AA, Gorbalenya AE, Ziebuhr J, Diederich WE. Structural basis for catalysis and substrate specificity of a 3C-like cysteine protease from a mosquito mesonivirus. Virology. 2019 May 2;533:21-33. doi: 10.1016/j.virol.2019.05.001. PMID:31078932 doi:http://dx.doi.org/10.1016/j.virol.2019.05.001
