Notes on Genus: Orthoreovirus
Type member: Mammalian orthoreovirus
This is one of the animal virus genera in the family Reoviridae
. Members have 10 segments, particles more than 70 nm in diameter and sedimentation coefficients greater than 600S.
Virions isometric (icosahedral), c.
85 nm in diameter, with a double capsid shell surrounding a core of c.
48 nm. Core particles have distinctive turrets at the fivefold axes.
Linear, double stranded RNA in 10 segments. Each virion contains a single copy of the entire genome. Total genome up to c.
24000 nucleotides long.
Genus Genomic Organization
Most segments have a single ORF. The segments are usually labelled as large (L1-3), medium (M1-3) or small (S1-4) with reference to their mobility in electrophoresis.
Type Member Genomic Organization
- Segment 1 (L1) (3854 nt) encodes the minor core RNA polymerase protein lambda-3 of 142.3 kDa
- Segment 2 (L2) (3915 nt) encodes the core spike protein lambda-2 of 143.9 kDa
- Segment 3 (L3) (3901 nt) encodes the major core protein lambda-1 of 141.9 kDa
- Segment 4 (M1) (2304 nt) encodes a protein (mu-2) of 83.3 kDa
- Segment 5 (M2) (2203 nt) encodes the outer core protein precursor mu-1 of 76.3 kDa
- Segment 6 (M3) (2241 nt) encodes the non-structural protein mu-NS of 80.2 kDa
- Segment 7 (S1) (1462 nt) encodes the minor capsid cell attachment protein sigma-1a of 45.5 kDa and a non-structural protein (sigma-ibNS) of 14.0 kDa
- Segment 8 (S2) (1331 nt) encodes a protein (sigma-2) of 37.7 kDa
- Segment 9 (S3) (1198 nt) encodes a non-structural RNA binding protein (sigma-NS) of 41.2 kDa
- Segment 10 (S4) (1196 nt) encodes the major capsid protein sigma-3 of 41.1 kDa