RNase P as hyperprocessing enzyme: A model for formation of a biologically functional tRNA fragment

Abstract

Hyperprocessing is defined as a further processing of mature RNA that produces another functional RNA. Hyperprocessing occurs inDrosophila cells. In the transposoncopia-related retrovirus-like particles ofDrosophila, a 39-nucleotide-long fragment from the 5′-region ofDrosophila initiator methionine tRNA is used as the primer forcopia minus-strand reverse transcription. This primer tRNA fragment is thought to be produced by cleavage within the mature tRNA sequence. We found that the catalytic RNA subunit of RNase P catalyzes this hyperprocessingin vitro and that this cleavage is dependent of the occurrence of an altered conformation of the tRNA substrate. In this review, I will summarize our work from the finding of the functional RNA fragment to the finding of a dynamic tRNA structure