Expression of protein-coding genes embedded in ribosomal DNA
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Steinar D. Johansen
Abstract
Ribosomal DNA (rDNA) is a specialised chromosomal location that is dedicated to high-level transcription of ribosomal RNA genes. Interestingly, rDNAs are frequently interrupted by parasitic elements, some of which carry protein genes. These are non-LTR retrotransposons and group II introns that encode reverse transcriptase-like genes, and group I introns and archaeal introns that encode homing endonuclease genes (HEGs). Although rDNA-embedded protein genes are widespread in nuclei, organelles and bacteria, there is surprisingly little information available on how these genes are expressed. Exceptions include a handful of HEGs from group I introns. Recent studies have revealed unusual and essential roles of group I and group I-like ribozymes in the endogenous expression of HEGs. Here we discuss general aspects of rDNA-embedded protein genes and focus on HEG expression from group I introns in the nucleolus.
©2007 by Walter de Gruyter Berlin New York
Articles in the same Issue
- 25 years of catalytic RNA: looking younger than ever!
- On the occasion of the 25th anniversary of the discovery of catalytic RNA
- An overview of the RNA world – for now
- Group II introns: structure, folding and splicing mechanism
- Expression of protein-coding genes embedded in ribosomal DNA
- Importance of tRNA interactions with 23S rRNA for peptide bond formation on the ribosome: studies with substrate analogs
- The spliceosome: a ribozyme at heart?
- A chemo-genetic approach for the study of nucleobase participation in nucleolytic ribozymes
- Long-range impact of peripheral joining elements on structure and function of the hepatitis delta virus ribozyme
- A 2′-methyl or 2′-methylene group at G+1 in precursor tRNA interferes with Mg2+ binding at the enzyme-substrate interface in E-S complexes of E. coli RNase P
- Morphing the minimal and full-length hammerhead ribozymes: implications for the cleavage mechanism
- Idiosyncratic cleavage and ligation activity of individual hammerhead ribozymes and core sequence variants thereof
- RNA self-processing towards changed topology and sequence oligomerization
- Plasminogen-dependent internalization of soluble melanotransferrin involves the low-density lipoprotein receptor-related protein and annexin II
- Could the effect of modeled microgravity on osteogenic differentiation of human mesenchymal stem cells be reversed by regulation of signaling pathways?
Articles in the same Issue
- 25 years of catalytic RNA: looking younger than ever!
- On the occasion of the 25th anniversary of the discovery of catalytic RNA
- An overview of the RNA world – for now
- Group II introns: structure, folding and splicing mechanism
- Expression of protein-coding genes embedded in ribosomal DNA
- Importance of tRNA interactions with 23S rRNA for peptide bond formation on the ribosome: studies with substrate analogs
- The spliceosome: a ribozyme at heart?
- A chemo-genetic approach for the study of nucleobase participation in nucleolytic ribozymes
- Long-range impact of peripheral joining elements on structure and function of the hepatitis delta virus ribozyme
- A 2′-methyl or 2′-methylene group at G+1 in precursor tRNA interferes with Mg2+ binding at the enzyme-substrate interface in E-S complexes of E. coli RNase P
- Morphing the minimal and full-length hammerhead ribozymes: implications for the cleavage mechanism
- Idiosyncratic cleavage and ligation activity of individual hammerhead ribozymes and core sequence variants thereof
- RNA self-processing towards changed topology and sequence oligomerization
- Plasminogen-dependent internalization of soluble melanotransferrin involves the low-density lipoprotein receptor-related protein and annexin II
- Could the effect of modeled microgravity on osteogenic differentiation of human mesenchymal stem cells be reversed by regulation of signaling pathways?
