Orthonairovirus (taxid:1980517)

Orthonairovirus is a genus of ssRNA- viruses in the Nairoviridae family that infect vertebrates and are transmitted by arthropods (arbovirus). In humans, these viruses can cause hemorrhagic fever.



Enveloped, spherical. Diameter from 80 to 120nm.



Segmented Negative-stranded RNA linear genome, L segment is between 6.8 and 12 kb, M segment between 3.2 and 4.9 kb and S segment between 1 and 3 kb.
Encodes for four to six proteins.


The viral RNA dependent RNA polymerase (L) binds to a promoter on each encapsidated segment, and transcribes the mRNA. Transcription is terminated by a strong hairpin sequence at the end of each gene. These are capped by L protein during synthesis using cap snatching .




  1. Virus attaches to host receptors though Gn-Gc glycoprotein dimer, and is endocytosed into vesicles in the host cell.
  2. Fusion of virus membrane with the vesicle membrane; ribonucleocapsid segments are released in the cytoplasm.
  3. Transcription, viral mRNAs are capped in the cytoplasm.
  4. Replication presumably starts when enough nucleoprotein is present to encapsidate neo-synthetized antigenomes and genomes.
  5. The ribonucleocapsids buds at Golgi apparatus, releasing the virion by exocytosis.

Host-virus interaction

Inhibition of host innate immunity

The nairovirus L protein contains an ovarian tumor domain-containing deubiquitinase that targets activated RIG-I to control innate immune signaling.

Matching UniProtKB/Swiss-Prot entries

(all links/actions below point to uniprot.org website)

11 entries grouped by strain

4 entries

Crimean-Congo hemorrhagic fever virus (strain Nigeria/IbAr10200/1970) (CCHFV) reference strain

NCAP_CCHFI Nucleoprotein (EC 3.1.-.-) (Nucleocapsid protein) (Protein N)
L_CCHFI RNA-directed RNA polymerase L (Protein L) (Large structural protein) (Replicase) (Transcriptase) ...
GP_CCHFI Envelopment polyprotein (M polyprotein) [Cleaved into: Mucin-like variable region; GP38; ...
NSS_CCHFI Non-structural protein (NSs)

3 entries

Dugbe virus (isolate ArD44313) (DUGV) reference strain

L_DUGBA RNA-directed RNA polymerase L (Protein L) (Large structural protein) (Replicase) (Transcriptase) ...
GP_DUGBA Envelopment polyprotein (M polyprotein) [Cleaved into: Mucin-like variable region; GP38; ...
NCAP_DUGBA Nucleoprotein (Nucleocapsid protein) (Protein N)

2 entries

Hazara virus (isolate JC280) reference strain

GP_HAZVJ Envelopment polyprotein (M polyprotein) [Cleaved into: GP38; Glycoprotein N (Gn) (Glycoprotein G2); ...
NCAP_HAZVJ Nucleoprotein (EC 3.1.-.-) (Nucleocapsid protein) (Protein N)

1 entry

Crimean-Congo hemorrhagic fever virus (isolate C68031) (CCHFV)

NCAP_CCHFV Nucleoprotein (Nucleocapsid protein) (Protein N)

1 entry

Dugbe virus

NCAP_DUGBV Nucleoprotein (Nucleocapsid protein) (Protein N)