Sequence analysis of genes encoding structural and nonstructural proteins of a human group B rotavirus detected in Calcutta, India

Nucleotide sequences of RNA segments encoding structural proteins(VP4, VP6, and VP7) and nonstructural proteins(NSP1 and NSP3) of a human group B rota virus CAL-1, which was detected in Calcutta, India, were determined and the ir relatedness with cognate genes of other group B rotaviruses was analyzed . The CAL-1 genes showed generally high sequence identifies (more than 90%) to those of human group B rotavirus, adult diarrheal rotavirus (ADRV) in C hina, while identities with bovine, murine, and ovine viruses were consider ably lower (58-73%). Among RNA segments analyzed, sequence identity of the VP6 gene was relatively high compared with other gene segments. In the CAL- 1 VP7 sequence, many characteristics were shared by ADRV, but not by other animal group 8 rotaviruses. In contrast, VP4 and NSP3 of CAL-1 were single animo acid and 23 amino acids longer than those of ADRV strain, respectivel y, due to differences of a few nucleotides. These findings suggested that h uman 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 th ese viruses. J. Med. Virol. 64:583-589, 2001. (C) 2001 Wiley-Liss, Inc.