6MRK

Crystal structure of dmNxf2 NTF2-like domain in complex with Nxt1/p15

Summary for 6MRK

• Entry DOI: 10.2210/pdb6mrk/pdb
• Descriptor: Nuclear RNA export factor 2, NTF2-related export protein (3 entities in total)
• Functional Keywords: piwi, transposon silencing, heterochromatin formation, pirna pathway, transcriptional silencing, rna binding protein
• Biological source: Drosophila melanogaster (Fruit fly); More
• Total number of polymer chains: 4
• Total formula weight: 77683.32

Authors

Wang, J.,Patel, D.J. (deposition date: 2018-10-13, release date: 2019-07-03, Last modification date: 2023-10-11)

Primary citation

Batki, J.,Schnabl, J.,Wang, J.,Handler, D.,Andreev, V.I.,Stieger, C.E.,Novatchkova, M.,Lampersberger, L.,Kauneckaite, K.,Xie, W.,Mechtler, K.,Patel, D.J.,Brennecke, J.
The nascent RNA binding complex SFiNX licenses piRNA-guided heterochromatin formation.
Nat.Struct.Mol.Biol., 26:720-731, 2019

PubMed Abstract: The PIWI-interacting RNA (piRNA) pathway protects genome integrity in part through establishing repressive heterochromatin at transposon loci. Silencing requires piRNA-guided targeting of nuclear PIWI proteins to nascent transposon transcripts, yet the subsequent molecular events are not understood. Here, we identify SFiNX (silencing factor interacting nuclear export variant), an interdependent protein complex required for Piwi-mediated cotranscriptional silencing in Drosophila. SFiNX consists of Nxf2-Nxt1, a gonad-specific variant of the heterodimeric messenger RNA export receptor Nxf1-Nxt1 and the Piwi-associated protein Panoramix. SFiNX mutant flies are sterile and exhibit transposon derepression because piRNA-loaded Piwi is unable to establish heterochromatin. Within SFiNX, Panoramix recruits heterochromatin effectors, while the RNA binding protein Nxf2 licenses cotranscriptional silencing. Our data reveal how Nxf2 might have evolved from an RNA transport receptor into a cotranscriptional silencing factor. Thus, NXF variants, which are abundant in metazoans, can have diverse molecular functions and might have been coopted for host genome defense more broadly.

PubMed: 31384064
DOI: 10.1038/s41594-019-0270-6

Experimental method

X-RAY DIFFRACTION (2.8 Å)