Genetic characteristics of field and attenuated rabies viruses ... - Evira

The nucleoprotein consists of 450 amino acids and participates in the transition
from RNA transcription to replication. It encapsidates the positive-strand leader RNA and
prevents further transcription of the genomic RNA (Wunner, 1991; Yang et al., 1998) and
contains several antigenic and immunodominant sites. The antigenic sites I and III
include stretches of amino acids at positions 374-383 and 313-337, respectively (Tordo,
1996). One of the immunodominant sites is known to be located at position 404-418
(Dietzschold et al., 1987; Ertl et al., 1989). Recently, the crystal structure of the rabies
virus nucleoprotein-RNA complex was determined (Albertini et al., 2006).
The P protein is a phosphorylated protein of 297 amino acids, associated with the
L protein to function as a noncatalytic cofactor for the RNA polymerization, and with the N
protein to support adequate RNA encapsidation (Chenik et al., 1994, 1998; Jacob et al.,
2001). Four additional proteins derived from the phosphoprotein gene of the rabies virus
were also found to be present in infected cells, cells transfected with a plasmid encoding
the wild-type P protein, and in the purified virus. It was shown that these proteins are
initiated from secondary downstream in-frame AUG initiation codons. The P-gene is the
only gene shown to encode more than one protein (Chenic et al., 1995). Two antigenic
sites were found to be located at positions 75-90 (Tordo, 1996). The domain 83-172 was
shown to contain the major antigenic determinants (Raux et al., 1997). An
immunodominant site was also mapped in phosphoprotein at positions 191-206 (Larson
et al., 1991), and was identified as the responsible alpha/beta interferon antagonist
(Brozka et al., 2005).
The matrix protein is a 202 amino acid polypeptide which plays a key role in virus
assembly and binding. It covers the ribonucleoprotein (RNP) coil to keep it in a
condensed form and was found to interact specifically with the glycoprotein (Mebatsion et
al., 1999). The major antigenic site is located between the amino acid residues 1 and 72
(Hiramatsu et al., 1992).
The glycoprotein is a 524 amino acid protein and is the most studied protein of the
rabies virus. It has a trimeric structure (Gaudin et al., 1992), with the first 19 amino acids
representing the signal domain which is found only in nascent protein. The glycoprotein
contains several antigenic sites and epitopes. The antigenic epitope I is represented by a
single amino acid at position 231 of the mature glycoprotein. The site II is known to be
discontinuous and involves two separate stretches between positions 34-42 and 198-200.
The antigenic site III is located at position 330-338, epitope VI at position 264, “a” – 342-
343 (Lafon et al., 1983, 1984; Seif et al., 1985; Prehaud et al., 1988; Bunschoten et
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