Non-enveloped. Small, icosahedral, about 60 nm in size. A single molecule of circular dsDNA is contained within the capsid, which is composed of 72 pentamers arranged on a T = 7 lattice.


Circular dsDNA, about 8 kb in size, associated with cellular histones.
On rare non-specific recombination, the viral genome can be integrated in host chromosome. This inactivates the integrated virus but can gives the host cell a replicative advantage sometimes leading to malignant tumours.


Only one strand of the genome is transcribed and yield two classes of proteins expressed by alternative splicing :
a) Early Proteins: non-structural regulatory proteins (E1-E7).
b) Late Proteins: the structural proteins L1 and L2.



Replication is divided in two distinct steps that are linked to the differentiation state of the host epithelial cell:

a) The plasmid replication takes place in the basal squamous epithelial cells. It corresponds to viral DNA replication in synchrony with the host cell chromosome in order to ensures an average of one viral genome per basal cell.

  1. Attachment of the viral proteins to host receptors mediates endocytosis into vesicles in the basal squamous epithelial cell.
  2. Transport to the nucleus and uncoating of the viral DNA.
  3. Early-region transcription and translation of the early proteins.
  4. Steady-state viral DNA nuclear replication. Requires the origin of DNA replication in cis and the viral E1 and E2 proteins in trans.

b) The vegetative replication, which occurs in differentiated keratinocytes. In these cells, which no longer undergo cellular DNA synthesis, there is a burst of viral DNA synthesis with active production of virions.

  1. Vegetative viral DNA synthesis.
  2. Transcription of the late region.
  3. Capsid proteins L1 and L2 synthesis.
  4. Nuclear capsid assembly and release of viruses.

Matching UniProtKB/Swiss-Prot entries

35 entries grouped by strain (browse by keywords)

9 entries

Bovine papillomavirus type 1 reference strain

VE6_BPV1 Protein E6
VL1_BPV1 Major capsid protein L1
VE5_BPV1 Protein E5
VE4_BPV1 Protein E4
VE2_BPV1 Regulatory protein E2
VL2_BPV1 Minor capsid protein L2
VE8E2_BPV1 Protein E8^E2C
VE1_BPV1 Replication protein E1 (EC (ATP-dependent helicase E1)
VE7_BPV1 Protein E7

8 entries

Deer papillomavirus (DPV) (Deer fibroma virus) reference strain

VE2_PAPVD Regulatory protein E2
VE7_PAPVD Protein E7
VL1_PAPVD Major capsid protein L1
VE6_PAPVD Protein E6
VL3_PAPVD Probable protein L3
VE1_PAPVD Replication protein E1 (EC (ATP-dependent helicase E1)
VE4_PAPVD Probable protein E4
VL2_PAPVD Minor capsid protein L2

7 entries

European elk papillomavirus (EEPV) reference strain

VE5_PAPVE Protein E5
VE7_PAPVE Protein E7
VE6_PAPVE Protein E6
VL1_PAPVE Major capsid protein L1
VE1_PAPVE Replication protein E1 (EC (ATP-dependent helicase E1)
VE2_PAPVE Regulatory protein E2
VL2_PAPVE Minor capsid protein L2

10 entries

Bovine papillomavirus type 2

VE2_BPV2 Regulatory protein E2
VE7_BPV2 Protein E7
VE6_BPV2 Protein E6
VE4_BPV2 Probable protein E4
VL2_BPV2 Minor capsid protein L2
VL1_BPV2 Major capsid protein L1
VE8_BPV2 Uncharacterized protein E8
VE3_BPV2 Probable protein E3
VE5_BPV2 Protein E5
VE1_BPV2 Replication protein E1 (EC (ATP-dependent helicase E1)

1 entry

Reindeer papillomavirus (RPV)

VE5_PAPVR Protein E5