7ql8 | pdb_00007ql8
SARS-COV2 Main Protease in complex with inhibitor MG78
Structural highlights
FunctionR1A_SARS2 Multifunctional protein involved in the transcription and replication of viral RNAs. Contains the proteinases responsible for the cleavages of the polyprotein.[UniProtKB:P0C6X7] Inhibits host translation by interacting with the 40S ribosomal subunit. The nsp1-40S ribosome complex further induces an endonucleolytic cleavage near the 5'UTR of host mRNAs, targeting them for degradation. Viral mRNAs are not susceptible to nsp1-mediated endonucleolytic RNA cleavage thanks to the presence of a 5'-end leader sequence and are therefore protected from degradation. By suppressing host gene expression, nsp1 facilitates efficient viral gene expression in infected cells and evasion from host immune response.[UniProtKB:P0C6X7] May play a role in the modulation of host cell survival signaling pathway by interacting with host PHB and PHB2. Indeed, these two proteins play a role in maintaining the functional integrity of the mitochondria and protecting cells from various stresses.[UniProtKB:P0C6X7] Responsible for the cleavages located at the N-terminus of the replicase polyprotein. In addition, PL-PRO possesses a deubiquitinating/deISGylating activity and processes both 'Lys-48'- and 'Lys-63'-linked polyubiquitin chains from cellular substrates. Participates together with nsp4 in the assembly of virally-induced cytoplasmic double-membrane vesicles necessary for viral replication. Antagonizes innate immune induction of type I interferon by blocking the phosphorylation, dimerization and subsequent nuclear translocation of host IRF3. Prevents also host NF-kappa-B signaling.[UniProtKB:P0C6X7] Participates in the assembly of virally-induced cytoplasmic double-membrane vesicles necessary for viral replication.[UniProtKB:P0C6X7] Cleaves the C-terminus of replicase polyprotein at 11 sites. Recognizes substrates containing the core sequence [ILMVF]-Q-|-[SGACN]. Also able to bind an ADP-ribose-1-phosphate (ADRP).[UniProtKB:P0C6X7] Plays a role in the initial induction of autophagosomes from host reticulum endoplasmic. Later, limits the expansion of these phagosomes that are no longer able to deliver viral components to lysosomes.[UniProtKB:P0C6X7] Forms a hexadecamer with nsp8 (8 subunits of each) that may participate in viral replication by acting as a primase. Alternatively, may synthesize substantially longer products than oligonucleotide primers.[UniProtKB:P0C6X7] Forms a hexadecamer with nsp7 (8 subunits of each) that may participate in viral replication by acting as a primase. Alternatively, may synthesize substantially longer products than oligonucleotide primers.[UniProtKB:P0C6X7] May participate in viral replication by acting as a ssRNA-binding protein.[UniProtKB:P0C6X7] Plays a pivotal role in viral transcription by stimulating both nsp14 3'-5' exoribonuclease and nsp16 2'-O-methyltransferase activities. Therefore plays an essential role in viral mRNAs cap methylation.[UniProtKB:P0C6X7] Publication Abstract from PubMedThe main protease (M(pro)) of the betacoronavirus SARS-CoV-2 is an attractive target for the development of treatments for COVID-19. Structure-based design is a successful approach to discovering new inhibitors of the M(pro). Starting from crystal structures of the M(pro) in complexes with the Hepatitis C virus NS3/4A protease inhibitors boceprevir and telaprevir, we optimized the potency of the alpha-ketoamide boceprevir against the M(pro) by replacing its P1 cyclobutyl moiety by a gamma-lactam as a glutamine surrogate. The resulting compound, MG-78, exhibited an IC50 of 13 nM versus the recombinant M(pro), and similar potency was observed for its P1' N-methyl derivative MG-131. Crystal structures confirmed the validity of our design concept. In addition to SARS-CoV-2 M(pro) inhibition, we also explored the activity of MG-78 against the M(pro) of the alphacoronavirus HCoV NL63 and against enterovirus 3C proteases. The activities were good (0.33 microM, HCoV-NL63 M(pro)), moderate (1.45 microM, Coxsackievirus 3C(pro)), and relatively poor (6.7 microM, enterovirus A71 3C(pro)), respectively. The structural basis for the differences in activities was revealed by X-ray crystallo-graphy. We conclude that the modified boceprevir scaffold is suitable for obtaining high-potency inhibitors of the coronavirus M(pro)s but further optimization would be needed to target enterovirus 3C(pro)s efficiently. From Repurposing to Redesign: Optimization of Boceprevir to Highly Potent Inhibitors of the SARS-CoV-2 Main Protease.,Gohl M, Zhang L, El Kilani H, Sun X, Zhang K, Bronstrup M, Hilgenfeld R Molecules. 2022 Jul 4;27(13). pii: molecules27134292. doi:, 10.3390/molecules27134292. PMID:35807537[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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