Table 1 Classification of EBOV and SARS-CoV in the 15-rank taxonomic hierarchy

From: The new scope of virus taxonomy: partitioning the virosphere into 15 hierarchical ranks

 

EBOV

SARS-CoV

Rank

Taxon

Demarcation criteria

Taxon

Demarcation criteria

Species

Zaire ebolavirusa

The species of the genus that includes the human pathogen EBOV.

Severe acute respiratory syndrome-related coronavirusb

The species of the subgenus, including the human pathogen SARS-CoV, that have diverged by less than 7.6% in the 3 CLpro, NiRAN, RdRp, ZBD and HEL1 domains of the replicase protein.

Subgenus

Unassigned

 

Sarbecovirusb

Members of the genus that have diverged by less than 14.7% in the 3CLpro, NiRAN, RdRp, ZBD and HEL1 domains of the replicase protein.

Genus

Ebolavirusa

Members of the family that use co-transcriptional editing to express several proteins from the G (GP) ORF and encode all other proteins from monocistronic genes.

Betacoronavirusb

Members of the subfamily that have diverged by less than 36.0% in the 3CLpro, NiRAN, RdRp, ZBD and HEL1 domains of the replicase protein.

Subfamily

Unassigned

 

Orthocoronavirinaeb

Members of the family that have diverged by less than 51.9% in the 3CLpro, NiRAN, RdRp, ZBD and HEL1 domains of the replicase protein.

Family

Filoviridae

Members of the order that infect vertebrates, produce filamentous virions and encode two proteins (VP30 and VP24) that do not have homologues in other order members.

Coronaviridaeb

Members of the suborder that have diverged by less than 68.3% in the 3CLpro, NiRAN, RdRp, ZBD and HEL1 domains of the replicase protein.

Suborder

Unassigned

 

Cornidovirineaeb

Members of the order that have diverged by less than 73.4% in the 3CLpro, NiRAN, RdRp, ZBD and HEL1 domains of the replicase protein.

Order

Mononegavirales

Members of the class that have a common, linear ORF core set (3’-N-P-M-G-L-5’).

Nidovirales

Members of the realm that share syntheny of 3CLpro, NiRAN, RdRp, ZBD and HEL1 domains of the replicase protein.

Subclass

Unassigned

 

Unassigned

 

Class

Monjiviricetes

As the subphylum currently includes only a single class, all members of the subphylum Haploviricotina are members of the class Monjiviricetes.

Unassigned

 

Subphylum

Haploviricotina

Members of the phylum with primary, non-segmented genomes encoding capping enzymes.

Unassigned

 

Phylum

Negarnaviricota

Members of the realm with negative-sense RNA genomes.

Unassigned

 

Subkingdom

Unassigned

 

Unassigned

 

Kingdom

Unassigned

 

Unassigned

 

Subrealm

Unassigned

 

Unassigned

 

Realm

Riboviria

Viruses with an RNA genome encoding an RNA-directed RNA polymerase.

Riboviria

Viruses with an RNA genome encoding an RNA-directed RNA polymerase.

  1. aPairwise sequence comparison42 using coding-complete filovirus genomes is the primary tool for filovirus species and genus demarcation. Genomic sequences of ebolaviruses of different species differ from each other by ≥23%. Genomic sequences of filoviruses of different genera differ from each other by ≥55%. Genomic features, such as number and location of gene overlaps, ebolavirus host and geographic distribution, and ebolavirus pathogenicity for different organisms, are also considered for species assignment, while genomic features, such as number and location of gene overlaps, number of open reading frames (ORFs) and/or genes, filovirus host and geographic distribution, and filovirus pathogenicity for different organisms, are also taken into account for genus assignment. Phylogenetic relationships across the genus have been established from maximum likelihood trees generated using coding-complete or complete genome sequences or by analysing filovirus large protein amino acid sequences43.
  2. bNidovirus taxa demarcation and rank assignment were defined by DivErsity pArtitioning by hieRarchical Clustering (DEmARC) analysis, a distance-based method with improved predictive power44 and inferred biological relevance45. The analysis sought minima of clustering cost in the distribution of pairwise distances derived from a maximum likelihood tree of the concatenated 3CLPro, NiRAN, RdRP, ZBD and HEL domains of the replicase polyprotein in all available sequences of viruses of the suborder Cornidovirineae. These minimum numbers were converted into percentages of amino acid identity that serve as a proxy for the selected minima. For the demarcation of the suborders, the order-wide analysis was performed. Members of the species, subgenus, genus, subfamily and family taxa form phylogenetically compact lineages in the Coronaviridae tree. Members of the suborder taxa form phylogenetically compact lineages in the Nidovirales tree (see ref. 46). 3CLpro, 3C-like protease; NiRAN, nidovirus RdRp-associated nucleotidyltransferase; RdRp, RNA-directed RNA polymerase; ZBD, Zn-binding domain covalently linked to HEL1; HEL1, helicase of superfamily 1.
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