Topoisomerase I promotes formation of a novel DNA intermediate in the ribosomal DNA
Molinar, T.; Sultanov, D.; Klein, H.; Hochwagen, A.
Show abstract
The ribosomal DNA (rDNA) is a conserved but highly unstable multi-gene locus that codes for the RNA components of the ribosome (rRNA). Despite being essential for protein translation and survival, rRNA gene-copy numbers fluctuate frequently. Here, we describe a novel rDNA intermediate that may be involved in these copy-number changes in Saccharomyces cerevisiae. Two-dimensional gel analyses revealed a structure that includes a large single-stranded tail and arises from the promoter of the 35S rRNA gene. Formation of this intermediate is unaffected by reduced 35S transcription but relies on topoisomerase I (Top1). Unexpectedly, intermediate formation is also independent of S phase or the rDNA-instability factor Fob1, even though Fob1 is mediates the major peak of Top1 cleavage complexes in the rDNA. Indeed, we find that the known rDNA instability phenotypes of top1 mutants, including increased formation of extrachromosomal rDNA circles, elevated genetic marker loss, and instability of critically short rDNA arrays, are also largely independent of Fob1. We therefore speculate that failure to form this intermediate leads to rDNA instability in top1 mutants.
Matching journals
The top 5 journals account for 50% of the predicted probability mass.
Similar papers in this journal
- Separable functions of Tof1/Timeless in intra-S-checkpoint signalling, replisome stability and DNA topological stress. 96%
- Transcription near arrested DNA replication forks triggers ribosomal DNA copy number changes 95%
- The Synaptonemal Complex Central Region Modulates Crossover Pathways and Feedback Control of Meiotic Double-strand Break Formation 95%
Similar papers in this journal
- Insights Into Ribosomal DNA (rDNA) Dominance and Magnification Through Characterization of Isogenic Deletion Alleles 96%
- A RAD9-dependent cell cycle arrest in response to unresolved recombination intermediates in Saccharomyces cerevisiae 96%
- Analysis of a Rpb2 mutant in Schizosaccharomyces pombe reveals a non-canonical role for Elp1 in regulating RNAi-dependent heterochromatin assembly 96%
Similar papers in this journal
- A genetic screen to identify factors affected by undecaprenyl phosphate recycling uncovers novel connections to morphogenesis in Escherichia coli 95%
- Roles of RodZ and Class A PBP1b in the Assembly and Regulation of the Peripheral Peptidoglycan Elongasome in Ovoid-Shaped Cells of Streptococcus pneumoniae D39 94%
- Translation inhibition from a distance: the small RNA SgrS interferes with a ribosomal protein S1-dependent enhancer 93%
Similar papers in this journal
- Primosomal protein PriC rescues replication initiation stress by bypassing the DnaA-DnaB interaction step for DnaB helicase loading at oriC 96%
- Surprising Phenotypic Diversity of Cancer-associated mutations of Gly 34 in the Histone H3 tail 96%
- Checkpoint inhibition of origin firing prevents inappropriate replication outside of S-phase 95%
Similar papers in this journal
"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.