A tRNA circularization assay: Evidence for the variation of the conformation of the CCA end

Abstract

The CCA end is common to all tRNAs as the universal site for amino acid attachment. It is also conserved in the 3′-terminal tRNA-like structure of viral genomes that can be aminoacylated by an aminoacyl-tRNA synthetase (Florentz & Giegé, 1995). During aminoacylation, the CCA end enters the catalytic center of an aminoacyl-tRNA synthetase and provides the site for chemistry to take place. The CCA end is also widely used in replication of retroviruses, the bacterial single-stranded RNA viruses, and duplex DNA plasmids of fungal mitochondria. During replication, the CCA end interacts with the template-specificity domain of reverse transcriptase or replicase and provides the initiation site for primer binding and extension (Maizels & Weiner, 1994). The importance of the CCA end in translation and in replication suggests that its conformation will play a role in these two fundamental processes.