L1 retrotransposition requires rapid ORF1p oligomerization, a novel coiled coil-dependent property conserved despite extensive remodeling.

ABSTRACT: Detailed mechanistic understanding of L1 retrotransposition is sparse, particularly with respect to ORF1p, a coiled coil-mediated homotrimeric nucleic acid chaperone that can form tightly packed oligomers on nucleic acids. Although the coiled coil motif is highly conserved, it is uniquely susceptible to evolutionary change. Here we studied three ORF1 proteins: a modern human one (111p), its resuscitated primate ancestor (555p) and a mosaic modern protein (151p) wherein 9 of the 30 coiled coil substitutions retain their ancestral state. While 111p and 555p equally supported retrotransposition, 151p was inactive. Nonetheless, they were fully active in bulk assays of nucleic acid interactions including chaperone activity. However, single molecule assays showed that 151p trimers form stably bo

SUBMITTER: Naufer MN 

PROVIDER: S-EPMC4705668 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature