Novel ATP-cone-driven allosteric regulation of ribonucleotide reductase via the radical-generating subunit

Autor: Inna Rozman Grinberg, Daniel Lundin, Mahmudul Hasan, Mikael Crona, Venkateswara Rao Jonna, Christoph Loderer, Margareta Sahlin, Natalia Markova, Ilya Borovok, Gustav Berggren, Anders Hofer, Derek T Logan, Britt-Marie Sjöberg
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: eLife, Vol 7 (2018)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.31529
Popis: 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 Å crystal structure. We also present evidence for an MnIIIMnIV 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.
Databáze: Directory of Open Access Journals