Leviviridae

=

VIRION

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

GENOME

Monopartite, linear, ssRNA(+) genome about 3.4-4.3 kb in size. The 5' end is capped. Encodes 3 (Allelovirus) or 4 proteins (Levivirus).

GENE EXPRESSION

The virion RNA is infectious and serves as both the genome and viral messenger RNA. Encodes 4 ORFs. Cp protein represses 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 Allolevivirus genus.

REPLICATION

  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

31 entries grouped by protein (browse by keywords)

All proteins are shown (view only 24 complete proteome entries)

3 entries

Minor capsid protein A1

Select_allDeselect_all
A1_BPMX1
Enterobacteria phage MX1 (Bacteriophage MX1) reference strain
A1_BPQBE
Escherichia phage Qbeta (Bacteriophage Q-beta) reference strain

Minor capsid protein A1 (A1 read-through protein)

A1_BPSP
Enterobacteria phage SP (Bacteriophage SP) reference strain

10 entries

Capsid protein (CP) (Coat protein)

Select_allDeselect_all
CAPSD_BPGA
Enterobacteria phage GA (Bacteriophage GA) reference strain
CAPSD_BPMS2
Escherichia phage MS2 (Bacteriophage MS2) reference strain
CAPSD_BPMX1
Enterobacteria phage MX1 (Bacteriophage MX1) reference strain
CAPSD_BPQBE
Escherichia phage Qbeta (Bacteriophage Q-beta) reference strain
CAPSD_BPSP
Enterobacteria phage SP (Bacteriophage SP) reference strain
CAPSD_BPF2
Enterobacteria phage f2 (Bacteriophage f2)
CAPSD_BPFR
Enterobacteria phage fr (Bacteriophage fr)
CAPSD_BPJP3
Enterobacteria phage JP34 (Bacteriophage JP34)
CAPSD_BPR17
Enterobacteria phage R17 (Bacteriophage R17)
CAPSD_BPZR
Enterobacteria phage ZR (Bacteriophage ZR)

2 entries

Coat protein

Select_allDeselect_all
COAT_BPPP7
Pseudomonas phage PP7 (Bacteriophage PP7)
COAT_BPPRR
Pseudomonas phage PRR1 (Bacteriophage PRR1)

4 entries

Lysis protein

Select_allDeselect_all
LYS_BPGA
Enterobacteria phage GA (Bacteriophage GA) reference strain
LYS_BPMS2
Escherichia phage MS2 (Bacteriophage MS2) reference strain

Lysis protein (L protein)

LYS_BPFR
Enterobacteria phage fr (Bacteriophage fr)
LYS_BPJP3
Enterobacteria phage JP34 (Bacteriophage JP34)

3 entries

Maturation protein A (MP) (Assembly protein) (A protein)

Select_allDeselect_all
MATA_BPGA
Enterobacteria phage GA (Bacteriophage GA) reference strain
MATA_BPMS2
Escherichia phage MS2 (Bacteriophage MS2) reference strain
MATA_BPFR
Enterobacteria phage fr (Bacteriophage fr)

3 entries

Maturation protein A2 (MP) (A2) (Assembly protein) (A protein)

Select_allDeselect_all
MATA2_BPMX1
Enterobacteria phage MX1 (Bacteriophage MX1) reference strain
MATA2_BPQBE
Escherichia phage Qbeta (Bacteriophage Q-beta) reference strain

Maturation protein A2 (MP) (A2 protein)

MATA2_BPSP
Enterobacteria phage SP (Bacteriophage SP) reference strain

6 entries

RNA-directed RNA polymerase beta chain (EC 2.7.7.48) (RNA replicase beta chain)

Select_allDeselect_all
RDRP_BPGA
Enterobacteria phage GA (Bacteriophage GA) reference strain
RDRP_BPMS2
Escherichia phage MS2 (Bacteriophage MS2) reference strain
RDRP_BPMX1
Enterobacteria phage MX1 (Bacteriophage MX1) reference strain

RNA-directed RNA polymerase subunit beta (EC 2.7.7.48) (RNA replicase beta chain)

RDRP_BPQBE
Escherichia phage Qbeta (Bacteriophage Q-beta) reference strain

RNA-directed RNA polymerase subunit beta (EC 2.7.7.48) (RNA replicase beta chain) (RNA-directed RNA polymerase subunit II)

RDRP_BPSP
Enterobacteria phage SP (Bacteriophage SP) reference strain

RNA-directed RNA polymerase subunit beta (EC 2.7.7.48) (RNA replicase beta chain)

RDRP_BPFR
Enterobacteria phage fr (Bacteriophage fr)