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

Rozman Grinberg, I.; Lundin, D.; Hasan, M.; Crona, M.; Jonna, V. R.; Loderer, C.; Sahlin, M.; Markova, N.; Borovok, I.; Berggren, G.; Hofer, A.; Logan, D. T.; Sjöberg, B.-M.

doi:10.1101/190033

bioRxiv · 10.1101/190033

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

Rozman Grinberg, I.·Lundin, D.·Hasan, M.·Crona, M.·Jonna, V. R.·Loderer, C.·Sahlin, M.·Markova, N.·Borovok, I.·Berggren, G.·Hofer, A.·Logan, D. T.·Sjöberg, B.-M.

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Abstract

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 [A] 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.

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Rozman Grinberg, I., Lundin, D., Hasan, M., Crona, M., Jonna, V. R., Loderer, C., Sahlin, M., Markova, N., Borovok, I., Berggren, G., Hofer, A., Logan, D. T., Sjöberg, B.-M.. 2017-09-17. Unique ATP-cone-driven allosteric regulation of ribonucleotide reductase via the radical-generating subunit. https://doi.org/10.1101/190033

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