PT  - JOURNAL ARTICLE
AU  - Corentin Claeys Bouuaert
AU  - Sam E. Tischfield
AU  - Stephen Pu
AU  - Eleni P. Mimitou
AU  - Ernesto Arias-Palomo
AU  - James M. Berger
AU  - Scott Keeney
TI  - Structural and functional characterization of the Spo11 core complex
AID  - 10.1101/2020.02.21.960211
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.02.21.960211
4099  - http://biorxiv.org/content/early/2020/02/24/2020.02.21.960211.short
4100  - http://biorxiv.org/content/early/2020/02/24/2020.02.21.960211.full
AB  - Spo11, which makes DNA double-strand breaks (DSBs) essential for meiotic recombination, is poorly understood mechanistically because it has been recalcitrant to biochemical study. Here, we provide a molecular analysis of S. cerevisiae Spo11 purified with partners Rec102, Rec104 and Ski8. Rec102 and Rec104 jointly resemble the B subunit of archaeal Topoisomerase VI, with Rec104 similar to a GHKL domain but without conserved ATPase motifs. Unexpectedly, the Spo11 complex is monomeric (1:1:1:1 stoichiometry), indicating that dimerization may control DSB formation. Reconstitution of DNA binding reveals topoisomerase-like preferences for duplex-duplex junctions and bent DNA. Spo11 also binds noncovalently but with high affinity to DNA ends mimicking cleavage products, suggesting a mechanism to cap DSB ends. Mutations that reduce DNA binding in vitro attenuate DSB formation, alter DSB processing, and reshape the DSB landscape in vivo. Our data reveal structural and functional similarities between the Spo11 core complex and Topo VI, but also highlight differences reflecting their distinct biological roles.