7e6r
Crystal structure of HCoV-NL63 3C-like protease,pH5.6
Structural highlights
FunctionR1A_CVHNL The papain-like proteinase 1 (PLP1) and papain-like proteinase 2 (PLP2) are responsible for the cleavages located at the N-terminus of the replicase polyprotein. In addition, PLP2 possesses a deubiquitinating/deISGylating activity and processes both 'Lys-48'- and 'Lys-63'-linked polyubiquitin chains from cellular substrates. PLP2 also antagonizes innate immune induction of type I interferon by blocking the nuclear translocation of host IRF-3. The main proteinase 3CL-PRO is responsible for the majority of cleavages as it cleaves the C-terminus of replicase polyprotein at 11 sites. Recognizes substrates containing the core sequence [ILMVF]-Q-|-[SGACN]. Inhibited by the substrate-analog Cbz-Val-Asn-Ser-Thr-Leu-Gln-CMK. Also contains an ADP-ribose-1-phosphate (ADRP)-binding function (By similarity). Nsp7-nsp8 hexadecamer may possibly confer processivity to the polymerase, maybe by binding to dsRNA or by producing primers utilized by the latter (By similarity). Nsp9 is a ssRNA-binding protein (By similarity). Publication Abstract from PubMedHuman coronavirus NL63 (HCoV-NL63), which belongs to the genus Alphacoronavirus, mainly infects children and the immunocompromized and is responsible for a series of clinical manifestations, including cough, fever, rhinorrhoea, bronchiolitis and croup. HCoV-NL63, which was first isolated from a seven-month-old child in 2004, has led to infections worldwide and accounts for 10% of all respiratory illnesses caused by etiological agents. However, effective antivirals against HCoV-NL63 infection are currently unavailable. The HCoV-NL63 main protease (M(pro)), also called 3C-like protease (3CL(pro)), plays a vital role in mediating viral replication and transcription by catalyzing the cleavage of replicase polyproteins (pp1a and pp1ab) into functional subunits. Moreover, M(pro) is highly conserved among all coronaviruses, thus making it a prominent drug target for antiviral therapy. Here, four crystal structures of HCoV-NL63 M(pro) in the apo form at different pH values are reported at resolutions of up to 1.78 A. Comparison with M(pro) from other human betacoronaviruses such as SARS-CoV-2 and SARS-CoV reveals common and distinct structural features in different genera and extends knowledge of the diversity, function and evolution of coronaviruses. Crystal structures of human coronavirus NL63 main protease at different pH values.,Gao H, Zhang Y, Jiang H, Hu X, Zhang Y, Zhou X, Zhong F, Lin C, Li J, Luo J, Zhang J Acta Crystallogr F Struct Biol Commun. 2021 Oct 1;77(Pt 10):348-355. doi:, 10.1107/S2053230X21009523. Epub 2021 Sep 27. PMID:34605439[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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