
<ArticleTitle>Sequence analysis of genes encoding structural and nonstructural proteins of a human group B rotavirus detected in Calcutta, India.</ArticleTitle>
<AbstractText>Nucleotide sequences of RNA segments encoding structural proteins(<prot>VP4</prot>, <prot>VP6</prot>, and <prot>VP7</prot>) and nonstructural proteins(<prot>NSP1</prot> and <prot>NSP3</prot>) of a human group B rotavirus CAL-1, which was detected in Calcutta, India, were determined and their relatedness with cognate genes of other group B rotaviruses was analyzed. The CAL-1 genes showed generally high sequence identities (more than 90%) to those of human group B rotavirus, adult diarrheal rotavirus (ADRV) in China, while identities with bovine, murine, and ovine viruses were considerably lower (58-73%). Among RNA segments analyzed, sequence identity of the <prot>VP6</prot> gene was relatively high compared with other gene segments. In the CAL-1 <prot>VP7</prot> sequence, many characteristics were shared by ADRV, but not by other animal group B rotaviruses. In contrast, <prot>VP4</prot> and <prot>NSP3</prot> of CAL-1 were single amino acid and 23 amino acids longer than those of ADRV strain, respectively, due to differences of a few nucleotides. These findings suggested that human group B rotaviruses CAL-1 and ADRV might have originated from a common ancestral virus distinct from animal group B rotaviruses reported so far, while some notable sequence differences indicated the distinct nature of these viruses.</AbstractText>
