The DNA within the eukaryotic nucleus is packaged as chromatin - a tight nucleoprotein complex composed of repeating units called nucleosomes. Pol II has developed a special mechanism to transcribe through such a tightly packed DNA. This project is aimed to investigate transcription by yeast Pol II elongation complexes through uniquely positioned nucleosome core in vitro. We apply recently developed experimental system employing assembly of authentic Pol II elongation complexes and ligation of these complexes to the mononucleosome in vitro. It has been found that this system faithfully recapitulates chief properties of the promoter-dependent experimental system such as the height and general properties of the nucleosomal barrier to transcription. We demonstrate that Pol II uses unique mechanism for transcription through chromatin. Surprising landmark of this mechanism is ability of the polymerase to transcribe through the nucleosome without accompanying change in nucleosome position observed in the case of all other analyzed RNA polymerases.
| Kireeva, Maria L; Hancock, Brynne; Cremona, Gina H et al. (2005) Nature of the nucleosomal barrier to RNA polymerase II. Mol Cell 18:97-108 |
| Studitsky, Vasily M; Walter, Wendy; Kireeva, Maria et al. (2004) Chromatin remodeling by RNA polymerases. Trends Biochem Sci 29:127-35 |
| Walter, W; Kireeva, M L; Tchernajenko, V et al. (2003) Assay of the fate of the nucleosome during transcription by RNA polymerase II. Methods Enzymol 371:564-77 |
| Walter, Wendy; Kireeva, Maria L; Studitsky, Vasily M et al. (2003) Bacterial polymerase and yeast polymerase II use similar mechanisms for transcription through nucleosomes. J Biol Chem 278:36148-56 |
| Kireeva, Maria L; Lubkowska, Lucyna; Komissarova, Natalia et al. (2003) Assays and affinity purification of biotinylated and nonbiotinylated forms of double-tagged core RNA polymerase II from Saccharomyces cerevisiae. Methods Enzymol 370:138-55 |
