Sequence analysis of three non structural proteins of a porcine group C (Cowden strain) rotavirus

Abstract

Sequences of three gene products of a group C (Cowden strain) rotavirus are presented and compared with the sequences of the corresponding group A (SA11) proteins. The degree of similarity for gene 7, 9, and 10 is respectively 34%, 58%, and 45%. Comparison of these 2 viruses allowed to identify several regions well conserved. In the protein coded by Cowden segment 7 (NS 53) only a short cystein and histidine rich region, presenting the zinc finger consensus motif, is common to group A (segment 5) and group C sequences. Conversely the protein coded by segment 9 (NS 35) presented marked homology with group A NS 35. The protein coded by segment 10 (NS 26) is serine rich and presents an accumulation of charged residues near the carboxy terminus, like group A counterpart. This genomic segment presented a single large open reading frame, that contrasts with the group A counterpart for which a second out of phase ORF is used in rotavirus infected MA 104 cells.

Biosynthesis and morphogenesis of group C rotavirus in swine testicular cells

“…of 83 kD is equivalent to the vp 4 hemagglutinin of group A rotavirus. In contrast to previous studies [3,9,11], we identified a polypeptide with a mol. wt.…”

“…[11] reported that group C rotavirus incorporated 3 H-mannose into two proteins, suggesting that group C rotavirus also contains high mannose glycoproteins. We found that 3 Hmannose was also incorporated into two polypeptides and like Bremont et al [3] we found one of these polypeptides to be a structural glycoprotein. These findings are, however, in contrast to a previous study [1 I] reporting a 25 kD possible structural glycoprotein in addition to the vp 7 structural glycoprotein.…”

“…Five structural potypeptides (97, 79, 78, 43, and 41 kD) were also immunoprecipitated in the RIPA which provided additional evidence for the structural status of the polypeptides detected in purified AmC-1 virus. Upon comparison to previous studies examining the biosynthesis of group C rotavirus on MA-104 cells and the protein composition of faeces purified group C rotavirus [3,9,11] there was an overall, although not total agreement in the number and molecular weights of the polypeptides. It has been conclusively demonstrated that group A rotavirus contains only high mannose glycoproteins [8,20].…”

“…Espejo et al [9] purified human group C rotavirus from faeces and identified six structural proteins with molecular weights ranking from 93 to 35kD. A similar study [3] of porcine group C rotavirus purified from faeces detected six structural polypeptides with molecular weights from 125 to 37 kD including a 39 kD glycoprotein. In a recent report on the biochemical properties of porcine group C rotavirus cultivated in MA-104 cells with subtoxic concentrations of pancreatin, 10 viral polypeptides were identified of which seven were designated structural and three regarded as non-structural [11].…”

Sequence conservation of the major outer capsid glycoprotein of human group C rotaviruses

“…Comparison with the porcine strain showed sequence heterogeneity was distributed throughout the protein with average identity of only 87.4%. The predicted molecular weight of the larger open reading frame (38 kDa) for the Bristol VP7 was in general agreement with the molecular weight determined by sodium dodecyl sulfate (SDS)-PAGE for the porcine (Cowden) VP7 glycoprotein [Bremont et al, 1988; Jiang et al, 19901. Three potential N-linked glycosylation sites (Asn-X-Ser/Thr) were present within the human sequences (at residues 67, 152, and 225) but only two in the porcine sequence at residues 67 and 225.…”