RNA polymerase (L) gene and genome terminal sequences of ephemeroviruses bovine ephemeral fever virus and Adelaide River virus indicate a close relationship to vesiculoviruses

The sequence of the RNA genome of bovine ephemeral fever virus (BEFV) was d etermined from the start of the L (polymerase) gene to the end of the untra nslated 5' trailer sequence, completing the sequence of the 14 900 nucleoti de (nt) genome. The 6470 nt L gene encodes a single long ORF of 2144 amino acids with a deduced molecular weight of 249 766 Da. The 70 nt BEFV 5' trai ler region displays partial terminal complementarity with the 3' leader seq uence and contains a 26 nt direct repeat of the U-rich domain of the 3' lea der region. The 47 nt 5' trailer region of Adelaide River virus (ARV) displ ays terminal sequence similarity to the BEFV trailer and partial terminal c omplementarity with the ARV 3' leader sequence, but does not contain the di rect repeat sequence. The BEFV L protein contains all characteristic sequen ce motifs of amino acid blocks I-VI, conserved among RNA polymerase protein s of single-stranded (-) RNA. viruses, separated by regions of lower homolo gy. Phylogenetic analysis using the complete BEFV L protein sequence indica ted a closer relationship to vesicular stomatitis virus than to rabies viru s. Sequence comparison of two conserved central domains encompassing blocks II and III and block VI of the BEFV and ARV L proteins indicated they are closely related. An extended phylogenetic analysis using the block III sequ ence, confirmed the relationship of these ephemeroviruses to vesiculo- and lyssaviruses and to other single-stranded (-) RNA viruses. (C) 2000 Elsevie r Science B.V. All rights reserved.