Title: A molecular sensor determines the ubiquitin substrate specificity of SARS-CoV-2 papain-like protease.
Authors: Patchett, Stephanie; Lv, Zongyang; Rut, Wioletta; Békés, Miklos; Drag, Marcin; Olsen, Shaun K; Huang, Tony T
Published In Cell Rep, (2021 09 28)
Abstract: The SARS-CoV-2 papain-like protease (PLpro) is a target for antiviral drug development. It is essential for processing viral polyproteins for replication and functions in host immune evasion by cleaving ubiquitin (Ub) and ubiquitin-like protein (Ubl) conjugates. While highly conserved, SARS-CoV-2 and SARS-CoV PLpro have contrasting Ub/Ubl substrate preferences. Using a combination of structural analyses and functional assays, we identify a molecular sensor within the S1 Ub-binding site of PLpro that serves as a key determinant of substrate specificity. Variations within the S1 sensor specifically alter cleavage of Ub substrates but not of the Ubl interferon-stimulated gene 15 protein (ISG15). Significantly, a variant of concern associated with immune evasion carries a mutation in the S1 sensor that enhances PLpro activity on Ub substrates. Collectively, our data identify the S1 sensor region as a potential hotspot of variability that could alter host antiviral immune responses to newly emerging SARS-CoV-2 lineages.
PubMed ID: 34547223
MeSH Terms: Amino Acid Sequence/genetics; Binding Sites/genetics; COVID-19/genetics; COVID-19/metabolism; Coronavirus Papain-Like Proteases/genetics; Coronavirus Papain-Like Proteases/metabolism*; Coronavirus Papain-Like Proteases/ultrastructure*; HEK293 Cells; Humans; Papain/chemistry; Papain/metabolism; Peptide Hydrolases/chemistry; Peptide Hydrolases/metabolism; Protein Binding/genetics; SARS-CoV-2/genetics*; SARS-CoV-2/metabolism; Substrate Specificity/genetics; Ubiquitin/metabolism; Ubiquitins/metabolism; Viral Proteins/metabolism