Work

The Fidelity of Transcription

Year: 2012

Type: article

Abstract: The fidelity of RNA synthesis depends on both accurate template-mediated nucleotide selection and proper maintenance of register between template and RNA. Loss of register, or transcriptional slippage, is particularly likely on homopolymeric runs in the template. Transcriptional slippage can alter the coding capacity of mRNAs and is used as a regulatory mechanism. Here we describe mutations in the largest subunit of Saccharomyces cerevisiae RNA polymerase II that substantially increase the level of transcriptional slippage. Alleles of RPB1 (RPO21) with elevated slippage rates were identified among 6-azauracil-sensitive mutants and were also isolated using a slippage-dependent reporter gene. Biochemical characterization of polymerase II isolated from these mutants confirms elevated levels of transcriptional slippage. Background: Yeast RNA polymerase II domains involved in maintenance of transcription register are unknown. Results: We isolated and biochemically characterized RPB1 mutations leading to register loss (transcription slippage). Conclusion: All RPB1 mutations affect slippage localize close to the active center and near the secondary pore of RNA polymerase II. Significance: Our results shed light on the mechanism of slippage by eukaryotic RNA polymerases.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.m112.429506