Extended Data Fig. 1. Mouse and freshwater sponge PIWI Argonaute proteins.

a, Overview of RNA Bind-’n-Seq. b, Sequences of small RNA guides used in this study. c, [E]_{active, apparent}, the apparent concentration of active MILI, MIWI, or EfPiwi piRISC, determined for each piRISC purification by fitting the cleavage data (from one experiment) to the burst-and-steady-state equation (see equation and fitting procedure in Analysis of Cleave-’n-Seq Data). d,e, Silver-stained SDS-PAGE gel showing representative purified MILI, MIWI, and EfPiwi piRISCs (d) and Coomassie-stained SDS-PAGE gel showing the purified EmGtsf1 and mouse GTSF1 used in the study (e). For gel source data, see Supplementary Fig. 1.