Coronavirus proteases are attractive targets for the design of antiviral drugs.

SARS-CoV-2 (2019-nCoV) coronavirus main protease, with inhibitor in turquoise. Download high quality TIFF image

In this world of fast and easy travel, emerging viruses are increasingly becoming a major danger to world health. Coronaviruses are a notable example. Particularly virulent forms have emerged from their natural animal hosts and pose a threat to human communities. In 2003, the SARS virus emerged in China from bat populations, moving to civets and finally to humans. Ten years later, the MERS virus also emerged from bats, transferring in the Middle East to dromedary camels and then to humans. Recently, another coronavirus has emerged in China by way of animals in a live market. Structural biology is helping us understand these dangerous foes, and hopefully will help us develop new ways to fight them.

Coronavirus Code

Coronaviruses contain a genome composed of a long RNA strand—one of the largest of all RNA viruses. This genome acts just like a messenger RNA when it infects a cell, and directs the synthesis of two long polyproteins that include the machinery that the virus needs to replicate new viruses. These proteins include a replication/transcription complex that makes more RNA, several structural proteins that construct new virions, and two proteases. The proteases play essential roles in cutting the polyproteins into all of these functional pieces.

Main Protease