Notes on Genus: Maculavirus


Type member: Grapevine fleck virus


General Description

The genus Maculavirus, one of three genera in the family Tymoviridae, is a small group of phloem-limited isometric viruses which are not sap-transmissible and with no known vectors. Phylogenetic analysis indicates some relationship to the other genera in the family but the genome size is larger and members of the genus Tymovirus are beetle-transmitted while those of the genus Marafivirus are transmitted by leafhoppers.


Virions isometric (icosahedral), not enveloped, c. 30 nm in diameter.


Monopartite, linear, single stranded, positive sense RNA approx. 7.5 kb in size. The 3' terminus has a poly(A) tract.

Genus Genomic Organization

Only the type member has been fully sequenced and this is believed to have four ORFs. The largest is a replication protein and the three smaller ones overlap and are probably translated from two or more subgenomic RNAs.

Type Member Genomic Organization

The RNA is translated from four open reading frames:
1   216 kDa Replication protein with methyltransferase and polymerase domains
2 24 kDa Coat protein
3 31 kDa proline rich; unknown function
4 16 kDa proline rich; unknown function