RT Journal Article
SR Electronic
T1 Unique ATP-cone-driven allosteric regulation of ribonucleotide reductase via the radical-generating subunit
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 190033
DO 10.1101/190033
A1 Inna Rozman Grinberg
A1 Daniel Lundin
A1 Mahmudul Hasan
A1 Mikael Crona
A1 Venkateswara Rao Jonna
A1 Christoph Loderer
A1 Margareta Sahlin
A1 Natalia Markova
A1 Ilya Borovok
A1 Gustav Berggren
A1 Anders Hofer
A1 Derek T Logan
A1 Britt-Marie Sjöberg
YR 2017
UL http://biorxiv.org/content/early/2017/09/17/190033.1.abstract
AB Ribonucleotide reductases (RNRs) are key enzymes in DNA synthesis and repair, with sophisticated allosteric mechanisms controlling both 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 Leewenhoekiella blandensis radical-generating subunit regulates activity via modifications of quaternary structure induced by binding of nucleotides. ATP induces enzymatically competent dimers, whereas dATP induces non-productive tetramers, resulting in different holoenzyme complexes. The tetramer forms solely by interactions between ATP-cones, as evidenced 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 evolutionary capture of the domain by the radical-generating subunit. Our findings present a novel opportunity for dATP-regulation of engineered proteins.