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bioRxiv · 10.1101/258194

Structure of Zip2:Spo16, a conserved XPF:ERCC1-like complex critical for meiotic crossover formation

Arora, K.·Corbett, K. D.
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Abstract

In eukaryotic meiosis, generation of haploid gametes depends on the formation of inter-homolog crossovers, which enable the pairing, physical linkage, and eventual segregation of homologs in the meiosis I division. A class of conserved meiosis-specific proteins, collectively termed ZMMs, are required for formation and spatial control of crossovers throughout eukaryotes. Here, we show that three S. cerevisiae ZMM proteins - Zip2, Zip4, and Spo16 - interact with one another and form a DNA-binding complex critical for crossover formation and control. We determined the crystal structure of a Zip2:Spo16 subcomplex, revealing a heterodimer structurally related to the XPF:ERCC1 endonuclease complex. Zip2:Spo16 lacks an endonuclease active site, but binds specific DNA structures found in early meiotic recombination intermediates. Mutations in multiple DNA-binding surfaces on the Zip2:Spo16 complex severely compromise DNA binding, supporting a model in which the complexs central and HhH domains cooperate to bind DNA. Overall, our data support a model in which the Zip2:Zip4:Spo16 complex binds and stabilizes early meiotic recombination intermediates, then coordinates additional factors to promote crossover formation and license downstream events including synaptonemal complex assembly.

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Arora, K., Corbett, K. D.. 2018-02-01. Structure of Zip2:Spo16, a conserved XPF:ERCC1-like complex critical for meiotic crossover formation. https://doi.org/10.1101/258194

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