Fig. 6

Sf-RVN cell R1 LINE transposons encode proteins with SF1H domains that are more similar to previously identified insect R1 LINE ORF2 proteins with C-terminal SF1H helicase domains, than to proteins from (+)ssRNA viruses. a Domain structure and relative size of full-length Sf-RVN and Plutella xylostella R1 LINE with SF1H domain. The size and order of conserved domains in ORF2 are very similar. b Predicted amino acid sequence alignment of SF1H domains of Sf-RVN and Plutella xylostella R1 LINEs, and Negev virus (YP_009256205.1) and TMV replicase (NP_597746.1). The shading is proportional to the degree of amino acid conservation. c Phylogenetic analysis of newly identified Sf-RVN and Plutella xylostella R1 LINE SF1H domains, and Negev virus and TMV replicase. The LINEs cluster closely together in a group that is distant from ssRNA viruses