Molecule of the Month: Coronavirus Proteases
Coronavirus proteases are attractive targets for the design of antiviral drugs.
Exploring the Structure
Bat Coronavirus Main Protease with Inhibitor
Researchers are actively using these structures to search for compounds that block the action of the proteases, for use as antiviral drugs. The diversity of coronaviruses poses a great challenge with this effort: coronaviruses have been classified into four separate genera, and sequence and structural studies have shown that the proteases of these viruses can be very different, so drugs designed to fight one may not be effective against others. One possible way to address this challenge is to try to design a broad-spectrum inhibitor targeted against the progenitor bat coronavirus, such as the one shown here from PDB entry 4yoi, which may then provide a head-start for discovering inhibitors against newly emerging viruses. The active site cysteine and histidine are shown in the illustration, with an inhibitor in turquoise. To explore this structure in more detail, click on the image for an interactive JSmol.
Topics for Further Discussion
- An unusual octameric form of the main protease may be involved in its maturation. You can see it in PDB entry 3iwm.
- You can compare the folds of coronavirus main proteases and serine proteases using the “Structure Align” tool. Try using trypsinogen (PDB entry 1tgs), so that the whole enzyme is one chain for the alignment.
February 2020, David Goodselldoi:10.2210/rcsb_pdb/mom_2020_2