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Catalytic function of DNA-dependent RNA polymerases
Sýkora, Michal ; Vopálenský, Václav (advisor) ; Lichá, Irena (referee)
DNA-dependent RNA polymerase is a highly organised protein complex that is responsible for gene expression and its regulation. Multisubunit RNA polymerase with its several catalytic activities is responsible for transcription of genes to RNA copies in all cellular organisms. During transcription RNA polymerase undergoes substantial conformational changes depending on the conditions in a particular cell. RNA polymerase in a state designated as an elongation complex passes through repetitive cycles of adding a nucleotide to the growing RNA chain. The active center contains two magnesium ions which coordinate the reactive groups of substrates. Furthermore, the active center contains structural elements that participate in binding of substrate, propper orientation of substrate towards the template strand and translocation of the RNA polymerase. The most important of these mobile structural elements are the bridge helix and the trigger loop whose conformational changes accompanies nucleotide addition cycle. Advances in the structural and biochemical characterization of RNA polymerase open new possibilities in the understanding of the transcription mechanism, its fidelity and control.
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Catalytic function of DNA-dependent RNA polymerases
Sýkora, Michal ; Vopálenský, Václav (advisor) ; Lichá, Irena (referee)
DNA-dependent RNA polymerase is a highly organised protein complex that is responsible for gene expression and its regulation. Multisubunit RNA polymerase with its several catalytic activities is responsible for transcription of genes to RNA copies in all cellular organisms. During transcription RNA polymerase undergoes substantial conformational changes depending on the conditions in a particular cell. RNA polymerase in a state designated as an elongation complex passes through repetitive cycles of adding a nucleotide to the growing RNA chain. The active center contains two magnesium ions which coordinate the reactive groups of substrates. Furthermore, the active center contains structural elements that participate in binding of substrate, propper orientation of substrate towards the template strand and translocation of the RNA polymerase. The most important of these mobile structural elements are the bridge helix and the trigger loop whose conformational changes accompanies nucleotide addition cycle. Advances in the structural and biochemical characterization of RNA polymerase open new possibilities in the understanding of the transcription mechanism, its fidelity and control.
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