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Related Experiment Video

Updated: Dec 24, 2025

Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods
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Viral cysteine proteinases.

Alexander E Gorbalenya1,2, Eric J Snijder3

  • 11M.P. Chumakov Institute of Poliomyelitis and Viral Encephalitides, Russian Academy of Medical Sciences, 142782 Moscow Region.

Perspectives in Drug Discovery and Design : PD3
|April 15, 2020
PubMed
Summary
This summary is machine-generated.

Novel viral cysteine proteinases, related to papain and chymotrypsin, are crucial for virus replication and host cell manipulation. Their structures reveal insights into catalysis and RNA binding.

Keywords:
ChymotrypsinCysteine ProteinasePapainSubstrate RecognitionVirion Entry

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Area of Science:

  • Virology
  • Enzymology
  • Structural Biology

Background:

  • Novel cysteine proteinases have been identified in various viruses, including RNA and DNA types.
  • These viral proteinases are often distantly related to papain or chymotrypsin, suggesting ancient origins.
  • They play critical roles in viral processes such as genome replication, virion assembly, and host cell entry.

Purpose of the Study:

  • To investigate the identification and functional significance of viral cysteine proteinases.
  • To explore the structural basis of catalysis, substrate recognition, and RNA binding in these enzymes.
  • To understand the diverse roles of viral cysteine proteinases in the viral life cycle.

Main Methods:

  • Identification of novel cysteine proteinases in viral genomes.
  • Comparative analysis of proteinase sequences and structures.
  • Biochemical assays to study enzymatic activity, substrate specificity, and RNA binding.
  • Three-dimensional structural analysis of viral cysteine proteinases.

Main Results:

  • Dozens of novel cysteine proteinases were found in positive-strand RNA viruses and large double-stranded DNA viruses.
  • These proteinases are structurally related to papain and chymotrypsin, possibly originating from primordial enzymes.
  • Viral cysteine proteinases control key steps in viral infection, including genome synthesis, virion formation, and host cell interaction.
  • RNA virus proteinases are liberated from precursor polyproteins and exhibit specific cleavage activities.
  • Structural studies elucidated mechanisms of catalysis, substrate recognition, and RNA binding for chymotrypsin-like viral cysteine proteinases.

Conclusions:

  • Viral cysteine proteinases are essential viral components with diverse functions in infection.
  • Their structural similarity to host enzymes suggests evolutionary links and potential for therapeutic targeting.
  • Understanding their structure-function relationships provides insights into viral mechanisms and antiviral strategies.