Medycyna Wet. 65 (9), 597-600, 2009
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| Niedbalski W., Kęsy A |
| Bluetongue virus (BTV): structure and replication |
| The article reviews the structure of BTV and the role of capsid proteins in the replication process. The BTV is an icosahedral virus with a genome of approximately 19 200 base pairs and composed of ten linear segments of double-stranded RNA (dsRNA). These RNA segments are packaged in a triple layered protein capsid (88 nm in diameter). The outer shell of capsid is composed of two structural proteins: 60 trimers of VP2, which acting as a hemagglutinin (HA) is responsible for glycoprotein receptor binding, and 120 trimers of VP5 that mediate the release of viral particles from endosomal compartments into cytoplasm and undergo pH dependent conformational changes that allow membrane fusion and syncytium formation. The intermediate layer consists of VP7 protein – the major immunodominant of BTV. This layer surrounds the subcore (54 nm) which consist of 12 decamers of the VP3 protein (role in the structural integrity of the virus core) and three minor structural proteins: VP1 (replicase), VP4 (mRNA capping enzyme) and VP6 (RNA-dependent ATPase and helicase). Moreover, the viral subcore consists of nonstructural proteins: NS1, NS2, NS3 and NS3A, which participate in the control of BTV replication, maturation and export from infected cell. |
| Keywords: bluetongue virus (BTV), structure, function of proteins, replication |