Lambdapapillomavirus (taxid:325462)



Non-enveloped. Small, icosahedral, about 52-55 nm in size. A single molecule of circular dsDNA is contained within the T=7 icosahedral capsid, which is composed of 72 pentamers.



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

(all links/actions below point to website)

7 entries grouped by strain

7 entries

Canine oral papillomavirus (strain Y62) (COPV) reference strain

VE2_COPV6 Regulatory protein E2
VE1_COPV6 Replication protein E1 (EC (ATP-dependent helicase E1)
VE7_COPV6 Protein E7
VE6_COPV6 Protein E6
VL2_COPV6 Minor capsid protein L2
VL1_COPV6 Major capsid protein L1
VE4_COPV6 Probable protein E4
These structures were created with the help of Colabfold by Jason Nomburg, Nathan Price and Jennifer Doudna (ModelArchive).

Canis familiaris papillomavirus 6 taxid:1513269

Protein ModelArchive
E4 ma-jd-viral-48045
Early protein 4 ma-jd-viral-48045
Major capsid protein L1 ma-jd-viral-67288
Minor capsid protein L2 ma-jd-viral-44964
Protein E6 ma-jd-viral-00876
Protein E7 ma-jd-viral-13713
Regulatory protein E2 ma-jd-viral-61148
Replication protein E1 (EC (ATP-dependent helicase E1) ma-jd-viral-21254

Enhydra lutris papillomavirus 1 taxid:1472717

Protein ModelArchive
E4 ma-jd-viral-48046
Major capsid protein L1 ma-jd-viral-67332
Minor capsid protein L2 ma-jd-viral-44971
Protein E6 ma-jd-viral-00914
Protein E7 ma-jd-viral-13722
Regulatory protein E2 ma-jd-viral-61144
Replication protein E1 (EC (ATP-dependent helicase E1) ma-jd-viral-21328

Felis domesticus papillomavirus 1 taxid:2847078

Protein ModelArchive
E4 protein ma-jd-viral-63112
Major capsid protein L1 ma-jd-viral-67277
Minor capsid protein L2 ma-jd-viral-44920
Protein E6 ma-jd-viral-00968
Protein E7 ma-jd-viral-13724
Regulatory protein E2 ma-jd-viral-61050
Replication protein E1 (EC (ATP-dependent helicase E1) ma-jd-viral-21333

Procyon lotor papillomavirus 1 taxid:312349

Protein ModelArchive
E4 ma-jd-viral-58434
Major capsid protein L1 ma-jd-viral-67334
Minor capsid protein L2 ma-jd-viral-44972
Protein E6 ma-jd-viral-00884
Protein E7 ma-jd-viral-13680
Regulatory protein E2 ma-jd-viral-61132
Replication protein E1 (EC (ATP-dependent helicase E1) ma-jd-viral-21300