(+) RNA virus helicase core domain (IPR027351)

Short name: (+)RNA_virus_helicase_core_dom

Overlapping homologous superfamilies

Domain relationships



Helicases have been classified in 6 superfamilies (SF1-SF6) [PMID: 22573863]. All of the proteins bind ATP and, consequently, all of them carry the classical Walker A (phosphate-binding loop or P-loop) and Walker B (Mg2+-binding aspartic acid) motifs. The two largest superfamilies, commonly referred to as SF1 and SF2, share similar patterns of seven conserved sequence motifs, some of which are separated by long poorly conserved spacers. Helicase motifs appear to be organised in a core domain which provides the catalytic function, whereas optional inserts and amino- and carboxy-terminal sequences may comprise distinct domains with diverse accessory roles. The helicase core contains two structural domains, an N- terminal ATP-binding domain and a C-terminal domain. Putative SF1 helicases are extremely widespread among positive-stranded (+)RNA viruses. They have been identified in a variety of plant virus families, as well as alpha- rubi-, arteri-, hepatitis E, and coronaviruses. A number of these viral enzymes have been implicated in diverse aspects of transcription and replication but also in RNA stability and cell-to-cell movement [PMID: 11000230].

The (+) RNA virus helicase core contains two RecA-like alpha/beta domains. The N-terminal ATP-binding domain contains a parallel six- stranded beta-sheet surrounded by four helices on one side and two helices on the other. The C-terminal domain contains a parallel four-stranded beta-sheet sandwiched between two helices on each of its sides. The (+)RNA virus helicase core is likely to bind NTP in cleft between the N terminus of the ATP-binding domain and the beginning of the C-terminal domain [PMID: 22573863].

This entry represents the (+)RNA virus helicase core domain.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005524 ATP binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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