Nucleotide sequence and deduced amino acid sequence of the medium RNA segment of Oropouche, a Simbu serogroup virus: Comparison with the middle RNA of Bunyamwera and California serogroup viruses

The Bunyavirus genus of the family Bunyaviridae contains 18 serogroups. To date nucleotide sequence data has been obtained for three serogroups, Bunya mwera, California and Simbu, based on analysis of the small (S) RNA segment . In comparison, there is only nucleotide sequence data for the large and m edium (M) RNA segments for members of the Bunyamwera and California serogro ups, In this paper we report the nucleotide sequence of the M RNA of Oropou che (ORO) virus, a member of the Simbu serogroup. The M RNA was 4396 nucleo tides in length with G1, G2 and NSm proteins similar in size to those repor ted for members of the Bunyamwera and California serogroups. However, there was limited nucleotide (50-52%) and amino acid (30-32%) homology between O RO virus M RNA and those of published members of the other two serogroups. The Bunyamwera and California serogroups are more closely related to each o ther than the Simbu serogroup virus Oropouche. These data were consistent w ith that previously reported for the S RNA (Saeed et al., 2000. J. Gen. Vir ol. 81, 743-748). It has been noted previously that three of four potential N-linked glycosylation sites of the Bunayamwera and California serogroups are conserved in G1 and G2 proteins. In contrast, ORO virus was found to ha ve only three potential N-linked glycosylation sites of which only one, in G1, was conserved with members of the other two serogroups. Comparison of M RNA sequences of different strains of ORO virus revealed genetic variation consistent with that reported previously for the S RNA. (C) 2001 Elsevier Science B.V. All rights reserved.