Begomovirus

VIRION

Non-enveloped, about 38 nm in length and 22 nm in diameter (for MSV), twinned (geminate) incomplete T=1 icosahedral symmetry capsid that contains 22 pentameric capsomers made of 110 capsid proteins (CP). Each geminate particle contains only a single circular ssDNA.

GENOME

Bipartite: components A and B (with some exceptions like TYLCV, ToLCV and AYVV which are monopartite), circular, ssDNA genome (+) of about 2.6 kb per component (5.2 kb in total). 3' terminus has no poly(A) tract. There are coding regions in both the virion (positive) and complementary (negative) sense strands.
The genome is replicated through double-stranded intermediates. The replication (Rep) protein initiates and terminates rolling circle replication, the host DNA polymerase being used for DNA replication itself. There is a potential stem-loop structure in the intergenic region that includes a conserved nonanucleotide sequence (TAATATTAC) where ssDNA synthesis is initiated. Component B is dependent on A for replication. The A and B components each have a common region (CR), which consists of a block of approximately 200bp within the IR and corresponds to the non-coding region common for topocu- and begomoviruses. The common region also contains two divergent promoters which differentially regulate the temporal expression of the viral genes.

GENE EXPRESSION

Transcription is bidirectional from the common region (CR). Proteins are expressed from subgenomic RNAs (sgRNAs). Leaky scanning is probably used for the expression of some of the overlapping proteins.

In bipartite begomoviruses, the A component encodes five or six proteins. On the v-sense: the CP. On the c-sense: Rep, a transcriptional activator (TrAP/AL2), a replication enhancer (REn), AC4, and, in some strains an optional protein AV2. The B component encodes two proteins involved in movement. BC1 on the c-sense and BV1 on the v-sense.

Monopartite begomoviruses encode six proteins: Rep, TrAP, CP, REn, C4, and V2.

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 released from the cell by budding
    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

Begomovirus protein Rep is responsible for inhibiting host retinoblastoma protein and inducing transition from the G1 to S phase in preparation for virus replication since the virus targets differentiated non-dividing cells. .

Suppression of host silencing-mediated antiviral defense

Begomovirus viral proteins are able to suppress host cell RNA silencing

Matching UniProtKB/Swiss-Prot entries

130 entries grouped by strain (browse by keywords)

All proteins are shown (view only 127 complete proteome entries)

9 entries

Indian cassava mosaic virus (ICMV) reference strain

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AC4_ICMV Protein AC4 (Protein AL4)
AV2_ICMV Protein AV2
CAPSD_ICMV Capsid protein (Coat protein) (CP)
MVP_ICMV Movement protein BC1 (Movement protein BL1)
NSP_ICMV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REN_ICMV Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
REP_ICMV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
YAL4_ICMV Putative uncharacterized protein AC5
TRAP_ICMV Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

8 entries

African cassava mosaic virus (isolate West Kenyan 844) (ACMV) (Cassava latent virus (isolate West Kenyan 844)) reference strain

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AC4_CLVK Protein AC4 (Protein AL4)
AV2_CLVK Protein AV2
CAPSD_CLVK Capsid protein (Coat protein) (CP)
MVP_CLVK Movement protein BC1 (33.7 kDa protein) (Movement protein BL1)
NSP_CLVK Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_CLVK Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (40.4 kDa protein) (Protein AC1) ...
REN_CLVK Replication enhancer protein (REn) (15.9 kDa protein) (Protein AC3) (Protein AL3)
TRAP_CLVK Transcriptional activator protein (TrAP) (15.2 kDa protein) (Protein AC2) (Protein AL2)

8 entries

Mungbean yellow mosaic virus (strain Vigna) (MYMV) reference strain

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AC4_MYMVV Protein AC4 (Protein AL4)
AV2_MYMVV Protein AV2
CAPSD_MYMVV Capsid protein (Coat protein) (CP)
MVP_MYMVV Movement protein BC1 (Movement protein BL1)
NSP_MYMVV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_MYMVV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
REN_MYMVV Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
TRAP_MYMVV Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

7 entries

Abutilon mosaic virus (isolate West India) (AbMV) reference strain

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AC4_ABMVW Protein AC4 (Protein AL4)
CAPSD_ABMVW Capsid protein (Coat protein) (CP)
MVP_ABMVW Movement protein BC1 (Movement protein BL1)
NSP_ABMVW Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_ABMVW Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
REN_ABMVW Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
TRAP_ABMVW Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

7 entries

Bean golden yellow mosaic virus (isolate Puerto Rico-Japan) (BGYMV) reference strain

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AC4_BGYMJ Protein AC4 (Protein AL4)
CAPSD_BGYMJ Capsid protein (Coat protein) (CP)
MVP_BGYMJ Movement protein BC1 (Movement protein BL1)
NSP_BGYMJ Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_BGYMJ Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (40.2 kDa protein) (Protein AC1) ...
REN_BGYMJ Replication enhancer protein (REn) (15.6 kDa protein) (Protein AC3) (Protein AL3)
TRAP_BGYMJ Transcriptional activator protein (TrAP) (19.6 kDa protein) (Protein AC2) (Protein AL2)

7 entries

Cabbage leaf curl virus (isolate Jamaica) (CaLCuV) reference strain

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AC4_CALCV Protein AC4 (Protein AL4)
CAPSD_CALCV Capsid protein (Coat protein) (CP)
MVP_CALCV Movement protein BC1 (Movement protein BL1)
NSP_CALCV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_CALCV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (40.2 kDa protein) (Protein AC1) ...
REN_CALCV Replication enhancer protein (REn) (15.6 kDa protein) (Protein AC3) (Protein AL3)
TRAP_CALCV Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

7 entries

Potato yellow mosaic virus (isolate Venezuela) (PYMV) reference strain

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AC4_PYMVV Protein AC4 (Protein AL4)
CAPSD_PYMVV Capsid protein (Coat protein) (CP)
MVP_PYMVV Movement protein BC1 (Movement protein BL1)
NSP_PYMVV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REN_PYMVV Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
REP_PYMVV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
TRAP_PYMVV Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

6 entries

Pepper huasteco yellow vein virus (PHYVV) (Pepper huasteco virus) reference strain

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AC4_PHUV Protein AC4 (Protein AL4)
CAPSD_PHUV Capsid protein (Coat protein) (CP)
NSP_PHUV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REN_PHUV Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
REP_PHUV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
TRAP_PHUV Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

6 entries

Tomato yellow leaf curl China virus (TYLCCNV) reference strain

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AC4_TYLCC Protein C4 (10.9 kDa protein) (Protein L4)
AV2_TYLCC Protein V2
CAPSD_TYLCC Capsid protein (Coat protein) (CP)
REP_TYLCC Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein C1)
REN_TYLCC Replication enhancer protein (REn) (Protein C3) (Protein L3)
TRAP_TYLCC Transcriptional activator protein (TrAP) (Protein C2) (Protein L2)

6 entries

Tomato yellow leaf curl Sardinia virus (TYLCSV) reference strain

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AC4_TYCSV Protein C4 (11.1 kDa protein) (Protein L4)
AV2_TYCSV Protein V2
CAPSD_TYCSV Capsid protein (Coat protein) (CP)
REP_TYCSV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein C1)
REN_TYCSV Replication enhancer protein (REn) (Protein C3) (Protein L3)
TRAP_TYCSV Transcriptional activator protein (TrAP) (Protein C2) (Protein L2)

6 entries

Tomato yellow leaf curl Sardinia virus (isolate Spain-2) (TYLCSV) reference strain

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AC4_TYCS2 Protein C4 (10.9 kDa protein) (Protein L4)
AV2_TYCS2 Protein V2
CAPSD_TYCS2 Capsid protein (Coat protein) (CP)
REN_TYCS2 Replication enhancer protein (REn) (Protein C3) (Protein L3)
REP_TYCS2 Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein C1)
TRAP_TYCS2 Transcriptional activator protein (TrAP) (Protein C2) (Protein L2)

6 entries

Tomato yellow leaf curl virus (strain Israel) (TYLCV) reference strain

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AC4_TYLCI Protein C4 (10.9 kDa protein) (Protein L4)
AV2_TYLCI Protein V2
CAPSD_TYLCI Capsid protein (Coat protein) (CP)
REP_TYLCI Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein C1)
REN_TYLCI Replication enhancer protein (REn) (15.6 kDa protein) (Protein C3) (Protein L3)
TRAP_TYLCI Transcriptional activator protein (TrAP) (Protein C2) (Protein L2)

8 entries

African cassava mosaic virus (isolate Nigerian) (ACMV) (Cassava latent virus (isolate Nigerian))

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AC4_CLVN Protein AC4 (Protein AL4)
AV2_CLVN Uncharacterized 13.1 kDa protein
CAPSD_CLVN Capsid protein (Coat protein) (CP)
MVP_CLVN Movement protein BC1 (33.7 kDa protein) (Movement protein BL1)
NSP_CLVN Nuclear shuttle protein (NSP) (29.4 kDa protein) (Protein BR1) (Protein BV1)
REP_CLVN Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (40.4 kDa protein) (Protein AC1) ...
REN_CLVN Replication enhancer protein (REn) (15.9 kDa protein) (Protein AC3) (Protein AL3)
TRAP_CLVN Transcriptional activator protein (TrAP) (15.2 kDa protein) (Protein AC2) (Protein AL2)

7 entries

Bean golden yellow mosaic virus (isolate Puerto Rico) (BGYMV) (Bean golden mosaic virus (isolate Puerto Rico))

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AC4_BGYMV Protein AC4 (Protein AL4)
CAPSD_BGYMV Capsid protein (Coat protein) (CP)
MVP_BGYMV Movement protein BC1 (Movement protein BL1)
NSP_BGYMV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_BGYMV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (40.2 kDa protein) (Protein AC1) ...
REN_BGYMV Replication enhancer protein (REn) (15.6 kDa protein) (Protein AC3) (Protein AL3)
TRAP_BGYMV Transcriptional activator protein (TrAP) (19.6 kDa protein) (Protein AC2) (Protein AL2)

7 entries

Squash leaf curl virus (SLCV)

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AC4_SLCV Protein AC4 (Protein AL4)
CAPSD_SLCV Capsid protein (Coat protein) (CP)
MVP_SLCV Movement protein BC1 (Movement protein BL1)
NSP_SLCV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REN_SLCV Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
REP_SLCV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
TRAP_SLCV Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

7 entries

Tomato golden mosaic virus (strain Yellow vein) (TGMV)

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AC4_TGMVY Protein AC4 (Protein AL4)
BC1_TGMVY Movement protein BC1 (Movement protein BL1)
CAPSD_TGMVY Capsid protein (Coat protein) (CP)
NSP_TGMVY Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_TGMVY Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
REN_TGMVY Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
TRAP_TGMVY Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

6 entries

Tomato leaf curl virus (strain Australia) (ToLCV)

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AC4_TLCVA Protein C4 (10.9 kDa protein) (Protein L4)
AV2_TLCVA Protein V2
CAPSD_TLCVA Capsid protein (Coat protein) (CP)
REP_TLCVA Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein C1)
REN_TLCVA Replication enhancer protein (REn) (Protein C3) (Protein L3)
TRAP_TLCVA Transcriptional activator protein (TrAP) (Protein C2) (Protein L2)

6 entries

Tomato mottle virus (isolate Florida) (ToMoV)

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CAPSD_TMOV Capsid protein (Coat protein) (CP)
BC1_TMOV Movement protein BC1 (Movement protein BL1)
NSP_TMOV Nuclear shuttle protein (NSP) (Protein BR1) (Protein BV1)
REP_TMOV Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein AC1) (Protein AL1)
REN_TMOV Replication enhancer protein (REn) (Protein AC3) (Protein AL3)
TRAP_TMOV Transcriptional activator protein (TrAP) (Protein AC2) (Protein AL2)

6 entries

Tomato yellow leaf curl Sardinia virus (isolate Spain-1) (TYLCSV)

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AC4_TYCS1 Protein C4 (10.9 kDa protein) (Protein L4)
AV2_TYCS1 Protein V2
CAPSD_TYCS1 Capsid protein (Coat protein) (CP)
REP_TYCS1 Replication-associated protein (Rep) (EC 2.7.7.-) (EC 3.1.21.-) (Protein C1)
REN_TYCS1 Replication enhancer protein (REn) (Protein C3) (Protein L3)
TRAP_TYCS1 Transcriptional activator protein (TrAP) (Protein C2) (Protein L2)