Picobirnaviruses encode a protein with repeats of the ExxRxNxxxE motif

Unité de Virologie et Immunologie moléculaires, UR892 INRA, F-78350 Jouy-en-Josas, France.
Virus Research (Impact Factor: 2.32). 03/2011; 158(1-2):251-6. DOI: 10.1016/j.virusres.2011.02.018
Source: PubMed


Picobirnaviruses possess a bisegmented double-stranded RNA genome. While the segment 2 encodes the RNA-dependent RNA polymerase, the segment 1 displays two open reading frames (ORFs). ORF2 was recently shown to code the capsid precursor and ORF1 product has not been characterized. In this study, we show that the three ORF1 sequences available in databases and representing three phylogenetically distant picobirnaviruses (two from human and one from rabbit hosts) encode proteins of various sizes (106-224 residues and without proline and cysteine) harbouring a particular sequence motif (ExxRxNxxxE) repeated four to ten times, depending on the virus species. Several algorithms predicted the three proteins to be mainly unfolded in the domains containing the repeats. The glycine-rich 25-40 amino acid long C-terminal domains containing hydrophobic residues with a periodicity of 3-4 residues are predicted structurally different of the upstream domains containing the motif repetitions. The ExxRxNxxxE sequence was not previously identified as a short linear motif in eukaryotic and prokaryotic proteins. Its function remains elusive.

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Available from: Stéphane Duquerroy, Sep 23, 2014
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    • "RNA segments of group A rotavirus (RVA) are numbered according to the electrophoretic mobility in polyacrylamide gel. from human: NC007026/human1 PBV [16] and GU968923/ human2 PBV [17] and one from rabbit: Picobirnavirus, AJ244022/rabbit PBV [18]) were found to carry a particular sequence motif (ExxRxNxxxE) which is repeated four to ten times, depending on the virus strains and encoded proteins of various sizes (106–224 residues and without proline and cysteine) [19]. While conscripting this paper in 2013, only two full length PBV genome sequences were available in nucleotide sequences databases, that is, GI/PBV/human/THAI/ Hy005102/2002 [16] and GI/PBV/California sea lion/Hong Kong/HKG-PF080915/2012 [20]. "
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