An alternative RNA polymerase I structure reveals a dimer hinge. (1st September 2015)

• Record Type: Journal Article
• Authors: Kostrewa, Dirk; Kuhn, Claus‐D.; Engel, Christoph; Cramer, Patrick
• Is Part Of: Acta crystallographica. Volume 71:Part 9(2015:Sep.)
• Page Start: 1850
• Page End: 1855
• Publication Date: 2015-09-01
• Subjects: Biomolecules -- Structure -- Periodicals; Physical biochemistry -- Periodicals; X-ray crystallography -- Periodicals; Crystallography -- Periodicals; 572
• DOI: 10.1107/S1399004715012651
• Languages: English
• ISSNs: 0907-4449

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>RNA polymerase I (Pol I) is the central, 14‐subunit enzyme that synthesizes the ribosomal RNA (rRNA) precursor in eukaryotic cells. The recent crystal structure of Pol I at 2.8 Å resolution revealed two novel elements: the `expander' in the active‐centre cleft and the `connector' that mediates Pol I dimerization [Engel <italic>et al.</italic> (2013), <italic>Nature (London)</italic>, <bold>502</bold>, 650–655]. Here, a Pol I structure in an alternative crystal form that was solved by molecular replacement using the original atomic Pol I structure is reported. The resulting alternative structure lacks the expander but still shows an expanded active‐centre cleft. The neighbouring Pol I monomers form a homodimer with a relative orientation distinct from that observed previously, establishing the connector as a hinge between Pol I monomers.</p> </abstract>