Characterization of non-canonical RNA polymerase encoded by the yeast linear plasmids

Transcription is the control point of gene expression. This process relies on protein complex of multisubunit RNA polymerases, which are extremely conserved among all cellular organisms. Transciption of extrachromosomal hereditary elements such as organelles, viruses and plasmids is dependent on host cellular RNA polymerases or intrinsic RNA polymerase is contained within these elements. Putative non-canonical two-subunit RNA polymerase is also encoded by linear cytoplasmic plasmids of the yeast Kluyveromyces lactis and most likely transcribes genes of these plasmids. Besides the two subunits of RNA polymerase encoded by linear plasmids of Kluyveromyces lactis there are another two estimated components of the transcription apparatus, namely capping enzyme that adds the cap to 5' mRNA ends and putative DExD/H box helicase. Characterization of the unique and underexplored transcription machinery of Kluyveromyces lactis plasmids was the principal objective of this work. The main goal was to: 1) clarify evolutionary origin of the linear plasmid transcription apparatus; 2) describe architecture of the linear plasmid transcription complex in vivo focused on putative RNA polymerase binding partners; 3) reveal mechanisms of transcription initiation and termination of the yeast linear plasmids. The main..