6W79

Structure of SARS-CoV main protease bound to potent broad-spectrum non-covalent inhibitor X77

• PDB DOI: https://doi.org/10.2210/pdb6W79/pdb

• Classification: VIRAL PROTEIN/INHIBITOR
• Organism(s): Severe acute respiratory syndrome coronavirus 2
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2020-03-18 Released: 2020-08-26 
• Deposition Author(s): Mesecar, A.D., StJohn, S., Center for Structural Genomics of Infectious Diseases (CSGID)
• Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.46 Å
• R-Value Free: 0.177 
• R-Value Work: 0.156 
• R-Value Observed: 0.157 

Starting Model: experimental

Literature

A taxonomically-driven approach to development of potent, broad-spectrum inhibitors of coronavirus main protease including SARS-CoV-2 (COVID-19)

Mesecar, A.D.

To be published.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 34.8 kDa 
• Atom Count: 3,120 
• Modelled Residue Count: 306 
• Deposited Residue Count: 306 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Main protease	A	306	Severe acute respiratory syndrome coronavirus 2	Mutation(s): 0
UniProt
Find proteins for P0C6X7 (Severe acute respiratory syndrome coronavirus) Explore P0C6X7  Go to UniProtKB:  P0C6X7

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
X77 (Subject of Investigation/LOI)	C [auth A]	N-(4-tert-butylphenyl)-N-[(1R)-2-(cyclohexylamino)-2-oxo-1-(pyridin-3-yl)ethyl]-1H-imidazole-4-carboxamide C27 H33 N5 O2 MUNFBYOTGGMQOS-XMMPIXPASA-N
MES	D [auth A], E [auth A]	2-(N-MORPHOLINO)-ETHANESULFONIC ACID C6 H13 N O4 S SXGZJKUKBWWHRA-UHFFFAOYSA-N
DMS	B [auth A]	DIMETHYL SULFOXIDE C2 H6 O S IAZDPXIOMUYVGZ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.46 Å
• R-Value Free: 0.177 
• R-Value Work: 0.156 
• R-Value Observed: 0.157 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 108.881	α = 90
b = 81.26	β = 104.231
c = 53.455	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
HKL-2000	data reduction
SCALEPACK	data scaling
PHENIX	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2020-08-26 
Deposition Author(s): Mesecar, A.D., StJohn, S., Center for Structural Genomics of Infectious Diseases (CSGID)

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)	United States	HHSN272201700060C

Revision History  

• Version 1.0: 2020-08-26
  Type: Initial release
  
• Version 1.1: 2023-10-18
  Changes: Data collection, Database references, Refinement description