Processing of Archaebacterial Intron-Containing tRNA Gene Transcripts

摘要

The goal of these studies was to establish model systems to investigate the interaction of proteins with nucleic acids in the Archaebacteria. The maturation of tRNA molecules in halophilic and thermophilic organisms was chosen for study. An assay was developed for the tRNA intron endonuclease from Halobacterium volcanii. This enzyme differed from its eukaryotic counterparts in substrate recognition and may participate in other RNA maturation reactions. Endonuclease was detected in a variety of Archaebacteria, including extreme thermophiles. Removal of 5' leader sequences from tRNA primary transcripts was also investigated. RNaseP activity was detected in H. volcanii and Thermoplasma. Preliminary findings indicate that this activity has an RNA component and may therefore be a ribozyme. The structure of stable RNA genes was examined in the extreme thermophile Methanothermus fervidus. In general, these RNAs have a greater degree of G-C base paring than mesophilic organisms suggesting that this property contributes to thermostability. Keywords: Molecule interactions; Archaebacteria; Intron; RNA processing; RNaseP; Halobacteria; Thermophiles; tRNA; DNA. (kt)