AUTHOR=Lazareva Ekaterina, Lezzhov Alexander, Vassetzky Nikita, Solovyev Andrey, Morozov Sergey TITLE=Acquisition of Full-Length Viral Helicase Domains by Insect Retrotransposon-Encoded Polypeptides JOURNAL=Frontiers in Microbiology VOLUME=6 YEAR=2015 URL=https://www.frontiersin.org/articles/10.3389/fmicb.2015.01447 DOI=10.3389/fmicb.2015.01447 ISSN=1664-302X ABSTRACT=Recent metagenomic studies in insects identified many sequences unexpectedly closely related to plant virus genes. Here we describe a new example of this kind, insect R1 LINEs with an additional C-terminal domain in their open reading frame 2. This domain is similar to NTPase/helicase (SF1H) domains, which are found in replicative proteins encoded by plant viruses of the genus Tobamovirus. We hypothesize that the SF1H domain could be acquired by LINEs, directly or indirectly, upon insect feeding on virus-infected plants. Possible functions of this domain in LINE transposition and involvement in LINEs counteraction the silencing-based cell defense against retrotransposons are discussed.