Fig. 2

Multiple sequence alignment of the RSV and PVM NS proteins. The GenBank accession numbers are: NP_044589.1 (RSV NS1), AHW80505.1 (RSV NS2), YP_173324.1 (PVM NS1), YP_173325.1 (PVM NS2). a Alignment by Clustal Omega, essentially showing the lack of any significant similarity among these proteins, perhaps in agreement with their differential effect on various ISGs. Only a few conservative replacements are denoted by dots. Amino acid residues, mapped to be important for RSV NS2 ubiquitination function [32], are underlined; note that they are also conserved in PVM NS2, in spite of the high dissimilarity in the overall sequences. The C-terminal tetrapeptide DLNP, double-underlined in the two NS proteins of RSV, may have a functional role in substrate degradation, as shown before [7]; it is not found in the PVM NS sequences. b Standard cladogram with similarity scores, generated by the default parameters of the same program, reveals that the NS1 and NS2 orthologs of the two viruses are slightly more similar to each other than NS1 and NS2 of the same virus, perhaps suggesting that NS1 and NS2 evolved independently