Related Experiment Video
Updated: Jun 15, 2025

Engineering Antiviral Agents via Surface Plasmon Resonance
Published on: June 14, 2022
Torsional Twist of the SARS-CoV and SARS-CoV-2 SUD-N and SUD-M domains
Monica Rosas-Lemus1,2, George Minasov1,2, Joseph S Brunzelle2,3
1Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Abstract:
Coronavirus non-structural protein 3 (nsp3) forms hexameric crowns of pores in the double membrane vacuole that houses the replication-transcription complex. Nsp3 in SARS-like viruses has three unique domains absent in other coronavirus nsp3 proteins. Two of these, SUD-N (Macrodomain 2) and SUD-M (Macrodomain 3), form two lobes connected by a peptide linker and an interdomain disulfide bridge. We resolve the first complete x-ray structure of SARS-CoV SUD-N/M as well as a mutant variant of SARS-CoV-2 SUD-N/M modified to restore cysteines for interdomain disulfide bond naturally lost by evolution. Comparative analysis of all structures revealed SUD-N and SUD-M are not rigidly associated, but rather, have significant rotational flexibility. Phylogenetic analysis supports that the disulfide bond cysteines are also absent in pangolin-SARS and closely related viruses, consistent with pangolins being the presumed intermediate host in the emergence of SARS-CoV-2. The absence of these cysteines does not impact viral replication or protein translation.
More Related Videos
Related Concept Videos
Conservation of Protein Domains
Conservation of Protein Domains Over Different Proteins
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
Angle of Twist - Elastic Range
Unsymmetric Bending - Angle of Neutral Axis
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
DNA Topoisomerases
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
Unsymmetric Bending

