Asparagine proteases

Asparagine proteases in viruses plays a role in capsid maturation. They are a type of enzyme that catalyze the cleavage of peptide bonds without hydrolysis and use a asparagine residue in their active site. (Wikipedia)

image

Enzymatic reaction: Enzymatic reaction:

  • Asn-endopeptidase

Mechanism
The active site consists of an asparagine and at least one acidic amino acid (Asp, Glu). The terminal asparagine azote acts as a nucleophile and attacks the carbonyl atom of the peptide bond, forming a succimide residue and cleaving the peptide bond; the acidic amino acid assists the process by stabilizing the reaction intermediates.

image

Viral molecular biology Virion
Virus entry
Virus latency
Transcription and replication
Host-virus interactions
Virus exit
Protein processing
Enterovirus 71 procapsid protein (Clan NE)

GenomeOrderFamilyFunctionTypeMEROPS familyDistribution (low incidence)Clan (fold)InterproUniProt exemplar
dsRNA Nodamuvirales imageimage Nodaviridae Self-cleavage, Virion maturation Asparagine (Asn/Ala) Peptidase N1 Virus NA
 IPR000696 Capsid protein precursor
ssRNA+ Hepevirales image Alphatetraviridae Self-cleavage, Virion maturation Asparagine (Asn/?) Peptidase N2 Virus NA
 IPR005313 Capsid protein precursor
ssRNA+ Durnavirales Picobirnaviridae Self-cleavage, Virion maturation Asparagine Peptidase N5 Virus NE
 Capsid protein precursor
dsRNA Reovirales imageimage Spinareoviridae, Orthoreovirus, Aquareovirus Self-cleavage, Virion maturation Asparagine Peptidase N7 Virus NC
 IPR009113 Outer capsid protein mu-1
ssRNA+ Picornavirales imageimage Picornaviridae, Enterovirus Self-cleavage, Virion maturation Asparagine Peptidase N8 Virus NA
 IPR029053 Polyprotein
ssRNA+ Imitervirales imageMimiviridae Self-cleavage, Intein Asparagine Peptidase N10 Animal, plant, protozoa, bacteria, archaea, virus PD
 IPR006141 DNA polymerase
ssRNA+ Algavirales imagePhycodnaviridae Self-cleavage, Intein Asparagine Peptidase N10 Animal, plant, protozoa, bacteria, archaea, virus PD
 IPR006141 DNA polymerase