Nanoviridae

VIRION

Non-enveloped, round, T=1 icosahedral symmetry, about 18-19 nm in diameter.

GENOME

Multipartite ssDNA genome (+) composed of 6 to 8 circular segments about 1kb in size. Each ssDNA segment have a common stem-loop region and are encapsidated in a separate particle .
In addition to genomic DNA, satellite-like DNA are commonly found, usually encoding for Rep proteins. These satellite-Rep proteins are only able to initiate replication of their genomic DNA, unlike genomic Rep which promotes replication of all 6-8 viral genomic ssDNAs.

GENE EXPRESSION

Each ssDNA genome segment is monocistronic. In rare cases a gene encodes for two overlapping ORFs.

REPLICATION

NUCLEAR

  1. Virus penetrates into the host cell.
  2. Uncoating, the viral ssDNA genome penetrates into the nucleus.
  3. The ssDNA is converted into dsDNA with the participation of cellular factors.
  4. Bidirectional dsDNA transcription from the IR promoter produces viral mRNAs and translation of viral proteins.
  5. Replication is initiated by cleavage of the (+)strand by REP, and occurs by rolling circle producing ssDNA genomes.
  6. These newly synthesized ssDNA can either
    a) be converted to dsDNA and serve as a template for transcription/replication
    b) be encapsidated by CP and form virions that will be released in the extracellular space. c) be transported outside the nucleus, to a neighboring cell through plasmodesmata (cell-cell movement) with the help of viral movement proteins.

Host-virus interaction

Cell-cycle modulation

Nanoviruses Clink protein is probably involved in binding and inhibiting host retinoblastoma protein. Inhibition of retinoblastoma protein induces transition from the G1 to S phase for optimal replication conditions.

Matching UniProtKB/Swiss-Prot entries

51 entries grouped by strain (browse by keywords)

All proteins are shown (view only 49 complete proteome entries)

8 entries

Subterranean clover stunt virus (strain F) (SCSV) reference strain

Select_all Deselect_all  
CAPSD_SCSVFCapsid protein (CP) (Coat protein)
CLINK_SCSVFCell cycle link protein (Clink)
MREP_SCSVFMaster replication protein (M-Rep) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3)
MVP_SCSVFPutative movement protein (MP)
NSP_SCSVFPutative nuclear shuttle protein
REP2_SCSVFPara-Rep C2 (Rep2) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
REP6_SCSVFPara-Rep C6 (Rep6) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
U1_SCSVFProtein U1

7 entries

Banana bunchy top virus (isolate Autralia) (BBTV) reference strain

Select_all Deselect_all  
CAPSD_BBTVACapsid protein (CP) (Coat protein)
CLINK_BBTVACell cycle link protein (Clink)
MREP_BBTVAMaster replication protein (M-Rep) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3)
MVP_BBTVAMovement and RNA silencing protein (MP)
NSP_BBTVAPutative nuclear shuttle protein
U3_BBTVAUncharacterized protein U3
U5_BBTVAUncharacterized 5 kDa protein in M-Rep ORF (Uncharacterized protein U5)

12 entries

Milk vetch dwarf virus (isolate N) (MDV)

Select_all Deselect_all  
CAPSD_MDV1Capsid protein (CP) (Coat protein)
CLINK_MDV1Cell cycle link protein (Clink)
MREP_MDV1Master replication protein (M-Rep) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3)
MVP_MDV1Putative movement protein (MP)
NSP_MDV1Putative nuclear shuttle protein
REP10_MDV1Para-Rep C10 (Rep10) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
REP1_MDV1Para-Rep C1 (Rep1) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
REP2_MDV1Para-Rep C2 (Rep2) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
REP3_MDV1Para-Rep C3 (Rep3) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
U1_MDV1Protein U1
U2_MDV1Protein U2
U4_MDV1Protein U4

11 entries

Faba bean necrotic yellows virus (isolate Egyptian EV1-93) (FBNYV)

Select_all Deselect_all  
CAPSD_FBNY1Capsid protein (CP) (Coat protein)
CLINK_FBNY1Cell cycle link protein (Clink)
MREP_FBNY1Master replication protein (M-Rep) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
MVP_FBNY1Putative movement protein (MP)
NSP_FBNY1Putative nuclear shuttle protein
REP1_FBNY1Para-Rep C1 (Rep1) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent ...
REP7_FBNY1Para-Rep C7 (Rep7) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent ...
REP9_FBNY1Para-Rep C9 (Rep9) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent ...
U1_FBNY1Protein U1
U2_FBNY1Protein U2
U4_FBNY1Protein U4

11 entries

Faba bean necrotic yellows virus (isolate SV292-88) (FBNYV)

Select_all Deselect_all  
CAPSD_FBNY2Capsid protein (CP) (Coat protein)
CLINK_FBNY2Cell cycle link protein (Clink)
MREP_FBNY2Master replication protein (M-Rep) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) ...
MVP_FBNY2Putative movement protein (MP)
NSP_FBNY2Putative nuclear shuttle protein
REP1_FBNY2Para-Rep C1 (Rep1) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent ...
REP7_FBNY2Para-Rep C7 (Rep7) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent ...
REP9_FBNY2Para-Rep C9 (Rep9) (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent ...
U1_FBNY2Protein U1
U2_FBNY2Protein U2
U4_FBNY2Protein U4

1 entry

Milk vetch dwarf virus (isolate 9) (MDV)


CAPSD_MDV9Capsid protein (CP) (Coat protein)

1 entry

Subterranean clover stunt virus (strain J) (SCSV)


CAPSD_SCSVJCapsid protein (CP) (Coat protein)