title: Trimeric structure and flexibility of the L1ORF1 protein in human L1 retrotransposition.
abstract: The LINE-1 (L1) retrotransposon emerges as a major source of human interindividual genetic variation, with important implications for evolution and disease. L1 retrotransposition is poorly understood at the molecular level, and the mechanistic details and evolutionary origin of the L1-encoded L1ORF1 protein (L1ORF1p) are particularly obscure. Here three crystal structures of trimeric L1ORF1p and NMR solution structures of individual domains reveal a sophisticated and highly structured, yet remarkably flexible, RNA-packaging protein. It trimerizes via an N-terminal, ion-containing coiled coil that serves as scaffold for the flexible attachment of the central RRM and the C-terminal CTD domains. The structures explain the specificity for single-stranded RNA substrates, and a mutational analysis indicates that the precise control of domain flexibility is critical for retrotransposition. Although the evolutionary origin of L1ORF1p remains unclear, our data reveal previously undetected structural and functional parallels to viral proteins.
authors.affiliation: Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany.
authors.forename: Elena
authors.initials: E
authors.lastname: Khazina
authors.forename: Vincent
authors.initials: V
authors.lastname: Truffault
authors.forename: Regina
authors.initials: R
authors.lastname: Büttner
authors.forename: Steffen
authors.initials: S
authors.lastname: Schmidt
authors.forename: Murray
authors.initials: M
authors.lastname: Coles
authors.forename: Oliver
authors.initials: O
authors.lastname: Weichenrieder
mesh_terms: D018360:Crystallography, X-Ray; D006801:Humans; D020084:Long Interspersed Nucleotide Elements; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*; D013379:Substrate Specificity
chemical_list: C531245:ORF1 protein, human; D011506:Proteins