5V5F

Crystal structure of RICE1 (PNT2)

Summary for 5V5F

• Entry DOI: 10.2210/pdb5v5f/pdb
• Descriptor: At3g11770 (1 entity in total)
• Functional Keywords: nuclease, mi-rna, transferase
• Biological source: Arabidopsis thaliana (Mouse-ear cress)
• Total number of polymer chains: 3
• Total formula weight: 68940.51

Authors

Li, P. (deposition date: 2017-03-14, release date: 2017-09-13, Last modification date: 2024-03-06)

Primary citation

Zhang, Z.,Hu, F.,Sung, M.W.,Shu, C.,Castillo-Gonzalez, C.,Koiwa, H.,Tang, G.,Dickman, M.,Li, P.,Zhang, X.
RISC-interacting clearing 3'- 5' exoribonucleases (RICEs) degrade uridylated cleavage fragments to maintain functional RISC in Arabidopsis thaliana.
Elife, 6:-, 2017

PubMed Abstract: RNA-induced silencing complex (RISC) is composed of miRNAs and AGO proteins. AGOs use miRNAs as guides to slice target mRNAs to produce truncated 5' and 3' RNA fragments. The 5' cleaved RNA fragments are marked with uridylation for degradation. Here, we identified novel cofactors of Arabidopsis AGOs, named RICE1 and RICE2. RICE proteins specifically degraded single-strand (ss) RNAs in vitro; but neither miRNAs nor miRNA*s in vivo. RICE1 exhibited a DnaQ-like exonuclease fold and formed a homohexamer with the active sites located at the interfaces between RICE1 subunits. Notably, ectopic expression of catalytically-inactive RICE1 not only significantly reduced miRNA levels; but also increased 5' cleavage RISC fragments with extended uridine tails. We conclude that RICEs act to degrade uridylated 5' products of AGO cleavage to maintain functional RISC. Our study also suggests a possible link between decay of cleaved target mRNAs and miRNA stability in RISC.

PubMed: 28463111
DOI: 10.7554/eLife.24466

Experimental method

X-RAY DIFFRACTION (2.945 Å)