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Mechanistic studies of transcription initiation by the yeast mitochondrial RNA polymerase
Author(s) -
Deshpande Aishwarya P,
Patel Smita S
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.549.2
Subject(s) - promoter , rna polymerase ii , transcription (linguistics) , sigma factor , rna polymerase , biology , polymerase , genetics , microbiology and biotechnology , rna , dna , gene , gene expression , linguistics , philosophy
The yeast mitochondrial DNA contains multiple promoters that direct the synthesis of rRNAs, tRNAs, and the mRNAs of the ATP synthesis complex. These RNAs are transcribed by a distinct two‐component complex consisting of the core RNA polymerase, Rpo41, which is the catalytic subunit and an accessory factor, Mtf1, which is necessary for promoter opening and start site selection. Although, currently we have a basic understanding of the mechanism of open complex formation and the respective roles of Rpo41 and Mtf1, we lack a similar understanding of the initial transcription mechanism involving +1 and +2 NTP binding and promoter strength. Using synthetic promoters, we observed a range of transcriptional efficiency from various promoters. Using promoter mutants and fluorescence‐based assays, we show that these differences in transcriptional efficiencies stem from differences in downstream promoter melting, which go hand in hand with differential NTP binding affinities. We propose a model, where either Rpo41 or Mtf1 or both through an orchestration of interactions with the promoter region as well as the incoming nucleotides regulate the transcriptional efficiency of various promoters. This work was supported by the NIH grant RM51966 to S.S.P