Summary information and primary citation
- PDB-id
-
5guh;
DSSR-derived features in text and
JSON formats
- Class
- hydrolase-RNA
- Method
- X-ray (2.4 Å)
- Summary
- Crystal structure of silkworm piwi-clade argonaute siwi
bound to pirna
- Reference
-
Matsumoto N, Nishimasu H, Sakakibara K, Nishida KM,
Hirano T, Ishitani R, Siomi H, Siomi MC, Nureki O (2016):
"Crystal
Structure of Silkworm PIWI-Clade Argonaute Siwi Bound to
piRNA." Cell, 167,
484-497.e9. doi: 10.1016/j.cell.2016.09.002.
- Abstract
- PIWI-clade Argonaute proteins associate with
PIWI-interacting RNAs (piRNAs) and silence transposable
elements in animal gonads. Here, we report the crystal
structure of a silkworm PIWI-clade Argonaute, Siwi, bound
to the endogenous piRNA, at 2.4 Å resolution. Siwi
adopts a bilobed architecture consisting of N-PAZ and
MID-PIWI lobes, in which the 5' and 3' ends of the bound
piRNA are anchored by the MID-PIWI and PAZ domains,
respectively. A structural comparison of Siwi with
AGO-clade Argonautes reveals notable differences in their
nucleic-acid-binding channels, likely reflecting the
distinct lengths of their guide RNAs and their mechanistic
differences in guide RNA loading and cleavage product
release. In addition, the structure reveals that Siwi and
prokaryotic, but not eukaryotic, AGO-clade Argonautes share
unexpected similarities, such as metal-dependent
5'-phosphate recognition and a potential structural
transition during the catalytic-tetrad formation. Overall,
this study provides a critical starting point toward a
mechanistic understanding of piRNA-mediated transposon
silencing.
