Reovirus

Reoviruses Rotavirus An inner core is surrounded by tv/o concentric icosahedral shells producing particles 70nm in diameter A very common cause of gastroenteritis in infants. It is spread through poor water supplies and when standards of general hygiene are low. In developing countries it is responsible for about a million deaths each year... 

B. Adenovirus, Reovirus, and Phage PRD1 Fiber Head Domains. 99... 

Fig. 1. Schematic drawings of the viruses discussed in this chapter. (A) An icosahe-dral virus with fiber proteins inserted in its pentameric vertices. The gray box denotes domains with known structures for adenovirus, reovirus, and bacteriophage PRD1, in each case containing the head domain and proximal part of the triple /8-spiral shaft domain. (B) Contractile-tailed bacteriophage T4. T4 contains three different fibrous proteins, fibritin connected to the neck, the long (bent) fibers connected to the base plate, and the short fibers also connected to the base plate. Only two of each of the trimeric fibrous proteins are shown for clarity. The gray box denotes domains with known structure for the T4 short fiber.

More recently, triple /1-spiral repeats have been identified in mammalian reovirus type 3 fiber (Chappell et al., 2002 Fig. 4A), avian reovirus fiber (Guardado Calvo et al., 2005 Fig. 4B), and bacteriophage PRD1 P5 protein (Merckel et al., 2005 Fig. 4C). In the latter two cases, it appears that only two repeats are present, just N-terminal to the head domain. Mammalian reovirus fiber contains eight putative triple /1-spiral repeats, of which three were resolved in the crystal structure (Chappell et al., 2002). 

Chappell, J. D., Prota, A. E., Dermody, T. S., and Stehle, T. (2002). Crystal structure of reovirus attachment protein sigmal reveals evolutionary relationship to adenovirus fiber. EMBOJ. 21, 1-11. 

Guardado Calvo, P., Fox, G. C., Hermo Parrado, X. L., Llamas-Saiz, A. L., Costas, C., Martinez-Costas, J., Benavente, J., and van Raaij, M. J. (2005). Structure of the carboxy-terminal receptor-binding domain of avian reovirus fibre sigmaC. / Mol. Biol. 354, 137-149. 

Where the structure of one or more similar viruses is available, low-resolution starting phases can be calculated from the model virus (or summed structures) correctly placed in the cell of the unknown structure (Fry et al., 1993). Cryo-EM reconstructions can provide adequate starting phases and envelope information for the determination of novel structures, for example BTV (Grimes effl/., 1998), Reovirus... 

Depicted here in this cartoon is a representation of various domains of the reovirus hemagglutinin. Some domains are overlapping whereas others are separate and unique from all the rest. The G5 domain appears to be the most relevant to the immune response and also for tropism. 

The anti-idiotypes in the reovirus system resemble hemagglutinin neutralization domains. Functionally shown here is the consequence of administering monoclonal anti-idiotypic proteins to mice. A variety of reovirus specific immune reactivities are induced. 

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