Gene 5 of the IDIR agent (group B rotavirus) encodes a protein equivalent to NS34 of group A rotavirus.

Gene 5 of the IDIR strain of group B rotavirus was cloned, sequenced, and expressed in RBC lysates in order to identify the coding assignment. The complete nucleic acid sequence of IDIR gene 5 included 1306 bases and encoded a single long open reading frame of 390 amino acids with a predicted molecular weight of 44.8 kDa. Comparison of the predicted amino acid sequence indicated substantial identity with the NS34 protein of group A rotaviruses (GAR). Like GAR NS34, the product deduced from IDIR agent gene 5 was predicted to exhibit a high degree of alpha helix secondary structure and a relatively low pl (4.6). In vitro translation of gene 5 resulted in synthesis of a protein which was specifically immunoprecipitated by convalescent antibody obtained from infant rats following infection with the IDIR agent, confirming that this product was of viral origin. Under non-reducing conditions, products as large as 200 kDa were also noted in SDS-PAGE. Formation of oligomers by GAR NS34 has previously been observed, indicating that this feature is probably a general characteristic among rotavirus NS34 and may relate to the functional role of the protein in viral replication.