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bioRxiv · 10.1101/2021.02.12.430902

Nse5/6 is a negative regulator of the ATPase activity of the Smc5/6 complex

Hallett, S. T.·Schellenberger, P.·Zhou, L.·Beuron, F.·Morris, E.·Murray, J. M.·Oliver, A.
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Abstract

The multi-component Smc5/6 complex plays a critical role in the resolution of recombination intermediates formed during mitosis and meiosis, and in the cellular response to replication stress. Using recombinant proteins, we have reconstituted a series of defined S. cerevisiae SMC5/6 complexes, visualised them by negative stain electron microscopy, and tested their ability to function as an ATPase. We find that only the six protein holo-complex is capable of turning over ATP and that its activity is significantly increased by the addition of double-stranded DNA to reaction mixes. Furthermore, stimulation is wholly dependent on functional ATP-binding pockets in both Smc5 and Smc6. Importantly, we demonstrate that budding yeast Nse5/6 acts as a negative regulator of Smc5/6 ATPase activity, binding to the head-end of the complex to suppress turnover, irrespective of the DNA-bound status of the complex.

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Hallett, S. T., Schellenberger, P., Zhou, L., Beuron, F., Morris, E., Murray, J. M., Oliver, A.. 2021-02-12. Nse5/6 is a negative regulator of the ATPase activity of the Smc5/6 complex. https://doi.org/10.1101/2021.02.12.430902

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