An evolutionarily conserved N-terminal domain of RRF-3 governs GTSF-1 binding in nematodes.

GTSF-1 binds to an N-terminal domain of RRF-3 across nematodes, supporting 26G-RNA biogenesis and fertility in Caenorhabditis and related species.

• Why it matters: Understanding this conserved interaction reveals how GTSF-1's role has shifted from PIWI activation to RRF-3 binding in nematodes, addressing gaps in knowledge about RNA regulation evolution.
• What they did: The study mapped the GTSF-1 and RRF-3 interaction to the GID domain, showed that the zinc finger region of GTSF-1 is sufficient for binding, and identified critical residues through mutagenesis in multiple nematode species.
• The result: Findings suggest GTSF-1 binding induces conformational changes in RRF-3 that promote RdRP complex assembly and activity, illuminating a conserved mechanism underlying nematode RNA pathways.