title: Acquisition of Full-Length Viral Helicase Domains by Insect Retrotransposon-Encoded Polypeptides.
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.
authors.affiliation: Department of Virology, Faculty of Biology, Lomonosov Moscow State University Moscow, Russia.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Lazareva
authors.affiliation: Department of Virology, Faculty of Biology, Lomonosov Moscow State University Moscow, Russia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lezzhov
authors.affiliation: Laboratory of Eukaryotic Genome Evolution, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences Moscow, Russia.
authors.forename: Nikita
authors.initials: N
authors.lastname: Vassetzky
authors.affiliation: Genetic Engineering of Plant Viruses, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University Moscow, Russia.
authors.forename: Andrey
authors.initials: A
authors.lastname: Solovyev
authors.affiliation: Department of Virology, Faculty of Biology, Lomonosov Moscow State UniversityMoscow, Russia; Genetic Engineering of Plant Viruses, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State UniversityMoscow, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Morozov
keywords: RNA silencing; RNA silencing suppressor; helicase; plant virus; retrotransposons