Paromomycin

Publication Title: 
The Journal of Biological Chemistry

We have determined the complete sequence of the nuclear gene encoding the small subunit (17 S) rRNA of the ciliated protozoan Tetrahymena thermophila. The gene encodes an RNA molecule which is 1753 nucleotides in length. The sequence of the Tetrahymena small subunit rRNA is homologous to those of other eukaryotes, and the predicted secondary structure for the molecule includes features which are characteristic of eukaryotic small subunit rRNAs.

Author(s): 
Spangler, E. A.
Blackburn, E. H.
Publication Title: 
Proceedings of the National Academy of Sciences of the United States of America

We transformed the ciliate Tetrahymena thermophila by microinjection of circular plasmids containing the ribosomal RNA gene (rDNA). In the somatic macronucleus of Tetrahymena, the rDNA is in the form of linear palindromic molecules. The rDNA molecules from the C3 strain have a replication advantage over rDNA from both B strain and the C3 rDNA mutant rmm1. We constructed two circular plasmids carrying replication origin sequences from C3 rDNA and a point mutation (Pmr) in the 17S rRNA gene that confers resistance to the antibiotic paromomycin.

Author(s): 
Yu, G. L.
Hasson, M.
Blackburn, E. H.
Publication Title: 
The Journal of Biological Chemistry

We have determined the complete sequence of the nuclear gene encoding the small subunit (17 S) rRNA of the ciliated protozoan Tetrahymena thermophila. The gene encodes an RNA molecule which is 1753 nucleotides in length. The sequence of the Tetrahymena small subunit rRNA is homologous to those of other eukaryotes, and the predicted secondary structure for the molecule includes features which are characteristic of eukaryotic small subunit rRNAs.

Author(s): 
Spangler, E. A.
Blackburn, E. H.
Publication Title: 
Proceedings of the National Academy of Sciences of the United States of America

A mutation that confers resistance to the drug paromomycin is shown to be in the structural gene that codes for the ribosomal RNA in Tetrahymena. This observation was made by exploiting a variant of the ribosomal DNA that distorts amplification of this locus when a new somatic nucleus develops during conjugation. Because the allelic forms of this locus have a restriction endonuclease site polymorphism, it was possible to correlate drug resistance with presence of a specific allele. The genetic results have been confirmed by sequence analysis (presented elsewhere).

Author(s): 
Bruns, P. J.
Katzen, A. L.
Martin, L.
Blackburn, E. H.
Subscribe to RSS - Paromomycin