Drosophila germ granules are assembled from protein components through different modes of competing interactions with the multi-domain Tudor protein.

Membraneless organelles are RNA-protein assemblies which have been implicated in post-transcriptional control. Germ cells form membraneless organelles referred to as germ granules, which contain conserved proteins including Tudor domain-containing scaffold polypeptides and their partner proteins that interact with Tudor domains. Here, we show that in Drosophila, different germ granule proteins associate with the multi-domain Tudor protein using different numbers of Tudor domains.