RPB6, a common subunit shared by all three eukaryotic RNA polymerases (RNAPI, RNAPII, and RNAPIII) contains a short N-terminal tail (NTT) of so far unknown function. Here, we have revealed that NTT interacts with the PH domain (PH-D) of the p62 subunit of the general transcription/repair factor TFIIH, and solved structures of RPB6 in its free and complexed forms with PH-D by NMR. Using available cryo-EM structures, the authors have modelled the activated elongation complex of RNAPII bound to TFIIH. In addition, the authors provide evidence that the p62-RPB6 interaction plays multiple roles in transcription, transcription-coupled nucleotide excision repair, and cell proliferation, suggesting that TFIIH is engaged in all RNA polymerase systems.
NAR’s Breakthrough Articles present high-impact studies answering long-standing questions in the field of nucleic acids research and/or opening up new areas and mechanistic hypotheses for investigation. These articles are chosen by the Editors on the recommendation of Editorial Board Members and Referees. Articles are accompanied by a brief synopsis explaining the findings of the paper and where they fit in the broader context of nucleic acids research. They represent the very best papers published at NAR.
Recent years have seen considerable progress in understanding the most important regulatory decision in DNA double strand break (DSB) – the transition to 5’ resection – which commits a DSB to repair via homologous recombination. Most approaches to study DSB resection begin to monitor resection 100s of bp from the DSB end. This represents a significant experimental gap, since all modern models of resection invoke critical actions of Mre11 and other proteins within the first hundred base pairs of the DSB end. The authors of this paper addressed this gap by developing a novel method with low background for high throughput sequencing of single molecules undergoing DSB resection in yeast. They were able to observe critical resection events as they happened in vivo, leading to substantive mechanistic insights such as the distance from the DSB end where Mre11 makes a key incision, which nucleases extend this nick most efficiently, and the speed with which various processing events occur ...
Cancer is a genomic disease, where mutations, translocations and chromosomal copy number aberrations drive tumor formation and progression. Isogenic cell line models to study mutations and translocations have given considerable insight into the biological mechanisms behind these aberrations, which has proven pivotal for the development of effective treatment modalities. However, the biological mechanisms that are driven by copy number changes remain elusive, since techniques to generate dedicated isogenic models have been lacking. Here the authors use the unprecedented genome editing capacity of CRISPR-Cas9 to establish a method to generate isogenic cell line models with large chromosomal deletions by essentially cutting out a large chromosomal region and stimulating correct repair with single stranded DNAs. This method is fast and efficient and will accelerate research on the oncogenicity of chromosomal copy number aberrations in cancer.
