Intron-containing tRNA precursors on both sides of the intron are divided by tRNA splicing endonuclease. Based on the experiment, the endonuclease uses different sets of structural elements which supersede the popular belief that the enzyme connects only to the mature domain by means of invariant bases. In the mature domain, a subset of recognition elements is necessary for recognition of both cleavage sites but in the exon-intron boundaries, two other subsets are utilized for recognition of either one or the other cleavage site. The findings advance the two-active model for eucaryal endonuclease.
Author: Negri, E. Di Nicola, Fabbri, S., Bufardeci, E., Baldi, M. I., Attardi, D. Gandini, Mattoccia, E., Tocchini-Valentini, G. P.
The gene encoding of the RNA intron endonucleases from the archaeon H. volcanii was cloned to understand the processing systems and relationship of archaeal and eucaryal tRNA introns. Under native conditions, a 37 kDa protein seemed present as a homodimer based on gene encodes. Based on the results of the analysis, the same proteins were present in Archaea and these proteins were similar to two subunits of the yeast tRNA intron endonuclease. Thus, it was revealed that there was a significant relationship between the archaeal and the eucaryal tRNA intron processing systems.
Author: Kleman-Leyer, Karen, Daniels, Charles J., Armbruster, David W.
Aechaeal histones' formation of nuclear DNA into nucleosomes and chromatin is a characteristic absent in bacteria since they have histone-like proteins that do not form DNA protein complexes related to nucleosome. The histone's order and the structure of the nucleosome are conserved in eucarya. As a result, homologs of eucaryal transcription-initiating system, are responsible for determining basal transcription-initiation in archaea.
Author: Reeve, John N., Sandman, Kathleen, Daniels, Charles J.