archaeal topoisomerase VI ( 31 ), which couples
adenosine 5 ́-triphosphate–dependent dimer-
ization of Top6B subunits to DNA cleavage by
Top6A subunits ( 32 ). Our predicted Rec102–
Spo11 complex resembles the Top6A–Top6B
interface: a four-helix bundle consisting of
two C-terminal helices from Rec102 and two
helices from Spo11 (the first helix of the
winged helix domain (WHD) plus a more
N-terminally located helix) (fig. S17D). Ala-nine substitutions in this portion of Rec102
disrupt interaction with Spo11 and block mei-
otic recombination in vivo ( 27 ). The model
clarifies the Spo11 portion of this interface,
which was not well structured in previousHumphreyset al.,Science 374 , eabm4805 (2021) 10 December 2021 4 of 12
Fig. 2. Protein complexes involved in transcription, translation, and DNA repair.Top predicted residue-residue contacts are indicated with bars. Pair color
indicates the method of identification: pairs from the“pooled experimental sets→AF”screen are in yellow and green, pairs from the“de novo RF→AF”screen are
in blue and light orange; and pairs present in both datasets are teal and pink. Full names of these proteins are in table S2.
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