View source for 8dox


==Crystal structure of SARS-CoV-2 main protease in complex with an inhibitor TKB-245==
<StructureSection load='8dox' size='340' side='right'caption='[[8dox]], [[Resolution|resolution]] 1.46&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8dox]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndrome_coronavirus_2 Severe acute respiratory syndrome coronavirus 2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8DOX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8DOX FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.46&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DMS:DIMETHYL+SULFOXIDE'>DMS</scene>, <scene name='pdbligand=T2L:(1R,2S,5S)-N-{(1S,2S)-1-(4-fluoro-1,3-benzothiazol-2-yl)-1-hydroxy-3-[(3S)-2-oxopyrrolidin-3-yl]propan-2-yl}-6,6-dimethyl-3-[3-methyl-N-(trifluoroacetyl)-L-valyl]-3-azabicyclo[3.1.0]hexane-2-carboxamide'>T2L</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8dox FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8dox OCA], [https://pdbe.org/8dox PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8dox RCSB], [https://www.ebi.ac.uk/pdbsum/8dox PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8dox ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/R1AB_SARS2 R1AB_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] (PubMed:32198291). Also able to bind an ADP-ribose-1''-phosphate (ADRP).[UniProtKB:P0C6X7]<ref>PMID:32198291</ref>   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]  Responsible for replication and transcription of the viral RNA genome.[UniProtKB:P0C6X7]  Multi-functional protein with a zinc-binding domain in N-terminus displaying RNA and DNA duplex-unwinding activities with 5' to 3' polarity. Activity of helicase is dependent on magnesium.[UniProtKB:P0C6X7]  Enzyme possessing two different activities: an exoribonuclease activity acting on both ssRNA and dsRNA in a 3' to 5' direction and a N7-guanine methyltransferase activity. Acts as a proofreading exoribonuclease for RNA replication, thereby lowering The sensitivity of the virus to RNA mutagens.[UniProtKB:P0C6X7]  Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond.[UniProtKB:P0C6X7]  Methyltransferase that mediates mRNA cap 2'-O-ribose methylation to the 5'-cap structure of viral mRNAs. N7-methyl guanosine cap is a prerequisite for binding of nsp16. Therefore plays an essential role in viral mRNAs cap methylation which is essential to evade immune system.[UniProtKB:P0C6X7]
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== Publication Abstract from PubMed ==
COVID-19 caused by SARS-CoV-2 has continually been serious threat to public health worldwide. While a few anti-SARS-CoV-2 therapeutics are currently available, their antiviral potency is not sufficient. Here, we identify two orally available 4-fluoro-benzothiazole-containing small molecules, TKB245 and TKB248, which specifically inhibit the enzymatic activity of main protease (M(pro)) of SARS-CoV-2 and significantly more potently block the infectivity and replication of various SARS-CoV-2 strains than nirmatrelvir, molnupiravir, and ensitrelvir in cell-based assays employing various target cells. Both compounds also block the replication of Delta and Omicron variants in human-ACE2-knocked-in mice. Native mass spectrometric analysis reveals that both compounds bind to dimer M(pro), apparently promoting M(pro) dimerization. X-ray crystallographic analysis shows that both compounds bind to M(pro)'s active-site cavity, forming a covalent bond with the catalytic amino acid Cys-145 with the 4-fluorine of the benzothiazole moiety pointed to solvent. The data suggest that TKB245 and TKB248 might serve as potential therapeutics for COVID-19 and shed light upon further optimization to develop more potent and safer anti-SARS-CoV-2 therapeutics.

Identification of SARS-CoV-2 M(pro) inhibitors containing P1' 4-fluorobenzothiazole moiety highly active against SARS-CoV-2.,Higashi-Kuwata N, Tsuji K, Hayashi H, Bulut H, Kiso M, Imai M, Ogata-Aoki H, Ishii T, Kobayakawa T, Nakano K, Takamune N, Kishimoto N, Hattori SI, Das D, Uemura Y, Shimizu Y, Aoki M, Hasegawa K, Suzuki S, Nishiyama A, Saruwatari J, Shimizu Y, Sukenaga Y, Takamatsu Y, Tsuchiya K, Maeda K, Yoshimura K, Iida S, Ozono S, Suzuki T, Okamura T, Misumi S, Kawaoka Y, Tamamura H, Mitsuya H Nat Commun. 2023 Feb 25;14(1):1076. doi: 10.1038/s41467-023-36729-0. PMID:36841831<ref>PMID:36841831</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Severe acute respiratory syndrome coronavirus 2]]
[[Category: Bulut H]]
[[Category: Das D]]
[[Category: Hayashi H]]
[[Category: Kuwata N]]
[[Category: Mitsuya H]]
[[Category: Tamamura H]]
[[Category: Tsuji K]]