Summary information and primary citation
- PDB-id
-
4d25;
DSSR-derived features in text and
JSON formats
- Class
- hydrolase
- Method
- X-ray (1.9 Å)
- Summary
- Crystal structure of the bombyx mori vasa helicase
(e339q) in complex with RNA and amppnp
- Reference
-
Xiol J, Spinelli P, Laussmann MA, Homolka D, Yang Z, Cora
E, Coute Y, Conn S, Kadlec J, Sachidanandam R, Kaksonen
M, Cusack S, Ephrussi A, Pillai RS (2014): "RNA
Clamping by Vasa Assembles a Pirna Amplifier Complex on
Transposon Transcripts."
Cell(Cambridge,Mass.), 157,
1698. doi: 10.1016/J.CELL.2014.05.018.
- Abstract
- Germline-specific Piwi-interacting RNAs (piRNAs)
protect animal genomes against transposons and are
essential for fertility. piRNAs targeting active
transposons are amplified by the ping-pong cycle, which
couples Piwi endonucleolytic slicing of target RNAs to
biogenesis of new piRNAs. Here, we describe the
identification of a transient Amplifier complex that
mediates biogenesis of secondary piRNAs in insect cells.
Amplifier is nucleated by the DEAD box RNA helicase Vasa
and contains the two Piwi proteins participating in the
ping-pong loop, the Tudor protein Qin/Kumo and antisense
piRNA guides. These components assemble on the surface of
Vasa's helicase domain, which functions as an RNA clamp to
anchor Amplifier onto transposon transcripts. We show that
ATP-dependent RNP remodeling by Vasa facilitates transfer
of 5' sliced piRNA precursors between ping-pong partners,
and loss of this activity causes sterility in Drosophila.
Our results reveal the molecular basis for the small RNA
amplification that confers adaptive immunity against
transposons.
