Severe acute respiratory syndrome coronavirus papain-like protease: Structure of a viral deubiquitinating enzyme
Ratia, K., Saikatendu, K.S., Santarsiero, B.D., Barretto, N., Baker, S.C., Stevens, R.C., Mesecar, A.D.(2006) Proc Natl Acad Sci U S A 103: 5717-5722
- PubMed: 16581910 
- DOI: https://doi.org/10.1073/pnas.0510851103
- Primary Citation of Related Structures:  
2FE8 - PubMed Abstract: 
Replication of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) requires proteolytic processing of the replicase polyprotein by two viral cysteine proteases, a chymotrypsin-like protease (3CLpro) and a papain-like protease (PLpro). These proteases are important targets for development of antiviral drugs that would inhibit viral replication and reduce mortality associated with outbreaks of SARS-CoV. In this work, we describe the 1.85-A crystal structure of the catalytic core of SARS-CoV PLpro and show that the overall architecture adopts a fold closely resembling that of known deubiquitinating enzymes. Key features, however, distinguish PLpro from characterized deubiquitinating enzymes, including an intact zinc-binding motif, an unobstructed catalytically competent active site, and the presence of an intriguing, ubiquitin-like N-terminal domain. To gain insight into the active-site recognition of the C-terminal tail of ubiquitin and the related LXGG motif, we propose a model of PLpro in complex with ubiquitin-aldehyde that reveals well defined sites within the catalytic cleft that help to account for strict substrate-recognition motifs.
Organizational Affiliation: 
Center for Pharmaceutical Biotechnology and Department of Medicinal Chemistry and Pharmacognosy, University of Illinois, Chicago, IL 60607, USA.