{"id":6028,"date":"2019-06-24T10:07:39","date_gmt":"2019-06-24T08:07:39","guid":{"rendered":"https:\/\/trigenotoul.com\/?p=6028"},"modified":"2019-06-24T10:07:39","modified_gmt":"2019-06-24T08:07:39","slug":"hyperactive-mutant","status":"publish","type":"post","link":"https:\/\/trigenotoul.com\/en\/mutant-super-actif\/","title":{"rendered":"A hyperactive mutant of the RNA polymerase dedicated to ribosome synthesis"},"content":{"rendered":"

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Ribosomes are, <\/strong>within the cells, <\/strong>the bodies responsible for <\/strong>the production of proteins. They are composed of an assembly of molecules including<\/strong>\u2019RNA polymerase I, an enzyme specifically responsible for the synthesis of RNA components<\/strong>. Researchers have managed to isolate a mutant polymerase that is more active than the normal enzyme. The existence of this \u00absuper-enzyme\u00bb producing more RNA sheds light on the biogenesis carried out in ribosomes and could constitute a primary target for certain cancers. These results, published in the journal PLoS Genetics<\/em>, have notably used a MeTi speciality, namely the single-molecule approach using electron microscopy.
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Capture of a Miller tree, also known as a Christmas tree because of their shape. The \u00abtrunk\u00bb of these trees is a DNA molecule, the \u00abbaubles\u00bb are various proteins, and the beads connecting the branches to the trunk are RNAs. Counting the \u00abbaubles\u00bb makes it possible to quantify protein production. Photo: MeTI<\/figcaption><\/figure>\n
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An open conformation, allowing the insertion of the template DNA into the catalytic centre (left), alternates with a closed conformation capable of maintaining the efficient capture of the short elongating DNA (right). Super-active mutants of RNA polymerase I (red on the central model) increase the enzyme's activity by facilitating the structural rearrangements necessary for the transition between these two forms (blue, yellow and red arrows).<\/figcaption><\/figure>\n
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