Qubevirus (taxid:2842995)

(formerly named Allolevivirus)



Non-enveloped, spherical virion about 26 nm in diameter with T=3 icosahedral symmetry composed of 178 CP proteins 889 dimers) and a single A2 maturation protein .



Monopartite, linear, ssRNA(+) genome about 4 kb in size. The 5' end is a triphosphate. Encodes 4 proteins.


The virion RNA is infectious and serves as both the genome and viral messenger RNA. Encodes for 4 ORFs. Cp protein repress replicase translation by binding a RNA hairpin at the start site of this gene. Lysis protein is expressed by suppression of termination of an UGA nonsense codon in levivirus genus (readthrough).



  1. Adsorption to F pili of target cells induces cleavage and release of the maturation protein.
  2. Genomic RNA enters the bacterium.
  3. Viral proteins are translated.
  4. Viral replicase assembles with host proteins (ribosomal protein S1, translation elongation factors EF-Tu and EF-Ts) to form the active RNA polymerase.
  5. Replication of genomic RNA into a minus strand, which serves as template to produce new positive strand genomes.
  6. Late in infection CP protein bind to a RNA hairpin on the genome, and new virus particles are assembled in the cytoplasm.
  7. Release by cell lysis.

Matching UniProtKB/Swiss-Prot entries

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

12 entries grouped by strain

4 entries

Enterobacteria phage SP (Bacteriophage SP) reference strain

CAPSD_BPSP Capsid protein (CP) (Coat protein)
RDRP_BPSP RNA-directed RNA polymerase subunit beta (EC (RNA replicase beta chain)
MATA2_BPSP Maturation protein A2 (MP) (A2) (Assembly protein) (A protein)
A1_BPSP Minor capsid protein A1

4 entries

Qbeta virus (strain MX1) reference strain

MATA2_BPMX1 Maturation protein A2 (MP) (A2) (Assembly protein) (A protein)
A1_BPMX1 Minor capsid protein A1
RDRP_BPMX1 RNA-directed RNA polymerase subunit beta (EC (RNA replicase beta chain)
CAPSD_BPMX1 Capsid protein (CP) (Coat protein)

4 entries

Escherichia virus Qbeta (Bacteriophage Q-beta)

CAPSD_BPQBE Capsid protein (CP) (Coat protein)
RDRP_BPQBE RNA-directed RNA polymerase subunit beta (EC (RNA replicase beta chain) (RNA-directed RNA ...
MATA2_BPQBE Maturation protein A2 (MP) (A2 protein)
A1_BPQBE Minor capsid protein A1 (A1 read-through protein)