Notes on Genus: Marburgvirus
Type member: Lake Victoria marburgvirus
The genus Marburgvirus
is one of two genera in the family Filoviridae
. It is named after the town of Marburg in Germany where the disease was first recognised. The virions are smaller than those of the genus Ebolavirus
and their are minor differences in genome organisation.
Virions pleomorphic but usually filamentous or bacilliform, enveloped, about 80 nm in diameter and 790nm long (although they may appear longer because of aggregation), with small (10 nm) projections.
Monopartite single-stranded negative sense RNA of about 19 kb. There is no genome-linked protein (VPg) at the 5'-terminus nor a 3'-polyA tail.
Genus Genomic Organization
There are 7 major ORFs with the RNA polymerase at the 5'-end of the genome and the capsid nucleoprotein at the 3'-end.
Type Member Genomic Organization
There are 7 major ORFs translated from positive sense template RNAs. They are listed here in their order on the template strand - i.e. from 3' to 5' with respect to the virion strand:
|1 ||NP||78 kDa || Coat protein (nucleocapsid)|
|2||VP35 ||36 kDa ||Phosphoprotein|
|3||VP40||34 kDa ||Matrix protein |
|4||GP ||75 kDa ||Glycoprotein precursor|
|5||VP30||32 kDa ||Virion protein |
|6||VP24||29 kDa ||Virion protein |
|7||L ||267 kDa ||Polymerase |