Domain

DNA helicase E1 protein, C-terminal, Papillomavirus (IPR001177)

Short name: DNA_helicase_E1_C_Papillomavir

Overlapping homologous superfamilies

Domain relationships

None.

Description

Papillomaviruses are a large family of DNA tumour viruses which give rise to warts in their host species. The helicase E1 protein is an ATP-dependent DNA helicase required for initiation of viral DNA replication [PMID: 8389467]. It forms a complex with the viral E2 protein, which is a site-specific DNA-binding transcriptional activator. The E1-E2 complex binds to the replication origin which contains binding sites for both proteins [PMID: 2176744].

The E1 protein is a 70kDa polypeptide with a central DNA-binding domain and a C-terminal ATPase/helicase domain. It binds specific 18 bp DNA sequences at the origin of replication, melts the DNA duplex and functions as a 3' to 5' helicase [PMID: 9060646]. In addition to E2 it also interacts with DNA polymerase alpha and replication protein A to effect DNA replication. The DNA-binding domain forms a five-stranded antiparallel beta sheet bordered by four loosely packed alpha helices on one side and two tightly packed helices on the other [PMID: 10949036]. Two structural modules within this domain, an extended loop and a helix, contain conserved residues and are critical for DNA binding. In solution E1 is a monomer, but binds DNA as a dimer. Recruitment of more E1 subunits to the complex leads to melting of the origin and ultimately to the formation of an E1 hexamer with helicase activity [PMID: 9658141].

The entry represents the C-terminal region of E1, containing both the DNA-binding and ATPase/helical domains.

GO terms

Biological Process

GO:0006260 DNA replication

Molecular Function

GO:0005524 ATP binding
GO:0003677 DNA binding
GO:0003678 DNA helicase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
Pfam