Cryo-EM structure of the Smc5/6 holo-complex

Hallett, S. T.; Campbell Harry, I.; Schellenberger, P.; Zhou, L.; Cronin, N. B.; Baxter, J.; Etheridge, T. J.; Murray, J. M.; Oliver, A. W.

doi:10.1101/2021.11.25.470006

bioRxiv · 10.1101/2021.11.25.470006

Cryo-EM structure of the Smc5/6 holo-complex

Hallett, S. T.·Campbell Harry, I.·Schellenberger, P.·Zhou, L.·Cronin, N. B.·Baxter, J.·Etheridge, T. J.·Murray, J. M.·Oliver, A. W.

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Abstract

The Smc5/6 complex plays an essential role in the resolution of recombination intermediates formed during mitosis or meiosis, or as a result of the cellular response to replication stress. It also functions as a restriction factor preventing viral integration. Here, we report the cryo-EM structure of the six-subunit budding yeast Smc5/6 holo-complex, reconstituted from recombinant proteins expressed in insect cells - providing a full overview of the complex in its apo / non-liganded form, and revealing how the Nse1/3/4 subcomplex binds to the hetero-dimeric SMC protein core. In addition, we demonstrate that a region within the head domain of Smc5, equivalent to the W-loop of Smc4 or F-loop of Smc1, mediates an essential interaction with Nse1. Taken together, these data confirm a degree of functional equivalence between the structurally unrelated KITE and HAWK accessory subunits associated with SMC complexes.

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Hallett, S. T., Campbell Harry, I., Schellenberger, P., Zhou, L., Cronin, N. B., Baxter, J., Etheridge, T. J., Murray, J. M., Oliver, A. W.. 2021-11-25. Cryo-EM structure of the Smc5/6 holo-complex. https://doi.org/10.1101/2021.11.25.470006

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