4GGJ:
reference: The structural biochemistry of Zucchini implicates it as a nuclease in piRNA biogenesis., Ipsaro JJ, Haase AD, Knott SR, Joshua-Tor L, Hannon GJ, Nature. 2012 Nov 8;491(7423):279-83. doi: 10.1038/nature11502. Epub 2012 Oct 14. PMID: 23064227

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