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Publication Abstract from PubMed

Ribonucleotide reductases (RNRs) are key enzymes in DNA metabolism, with allosteric mechanisms controlling substrate specificity and overall activity. In RNRs, the activity master-switch, the ATP-cone, has been found exclusively in the catalytic subunit. In two class I RNR subclasses whose catalytic subunit lacks the ATP-cone, we discovered ATP-cones in the radical-generating subunit. The ATP-cone in the Leeuwenhoekiella blandensis radical-generating subunit regulates activity via quaternary structure induced by binding of nucleotides. ATP induces enzymatically competent dimers, whereas dATP induces non-productive tetramers, resulting in different holoenzymes. The tetramer forms by interactions between ATP-cones, shown by a 2.45 A crystal structure. We also present evidence for an Mn(III)Mn(IV) metal center. In summary, lack of an ATP-cone domain in the catalytic subunit was compensated by transfer of the domain to the radical-generating subunit. To our knowledge, this represents the first observation of transfer of an allosteric domain between components of the same enzyme complex.

Novel ATP-cone-driven allosteric regulation of ribonucleotide reductase via the radical-generating subunit.,Rozman Grinberg I, Lundin D, Hasan M, Crona M, Jonna VR, Loderer C, Sahlin M, Markova N, Borovok I, Berggren G, Hofer A, Logan DT, Sjoberg BM Elife. 2018 Feb 1;7. pii: 31529. doi: 10.7554/eLife.31529. PMID:29388911^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.