Nucleotide sequences of the F, L and G protein genes of two non-A/non-B avian pneumoviruses (APV) reveal a novel APV subgroup

Sequence analysis was performed of all or part of the genes encoding the fu sion (F), polymerase (L) and attachment (G) proteins of two French non-A/no n-B avian pneumovirus (APV) isolates (Fr/85/1 and Fr/85/2), The two isolate s shared at least 99.7% nt and 99.0% aa sequence identity. Comparison with the F genes from subgroup A, subgroup B or Colorado APVs revealed nt and aa identities of 70.0-80.5% and 77.6-97.2%, respectively, with the L gene sha ring 76.1% nt and 85.3% aa identity with that of a subgroup A isolate. The Fr/85/1 and Fr/85/2 G genes comprised 1185 nt, encoding a protein of 389 aa , Common features with subgroup A and subgroup B G proteins included an ami no-terminal membrane anchor, a high serine and threonine content, conservat ion of cysteine residues and a single extracellular region of highly conser ved sequence proposed to be the functional domain involved in virus attachm ent to cellular receptors, However, the Fr/85/1 and Fr/85/2 G sequences sha red at best 56.6% nt and 31.2% aa identity with subgroup A and B APVs, wher eas these isolates share 38% aa identity. Phylogenetic analysis of the F, G and L genes of pneumoviruses suggested that isolates Fr/85/1 and Fr/85/2 b elong to a previously unrecognized APV subgroup, tentatively named D. G-bas ed oligonucleotide primers were defined for the specific molecular identifi cation of subgroup D, These are the first G protein sequences of non-A/non- B APVs to be determined.