3LUG

Crystal structure of MID domain from hAGO2 in complex with CMP

3LUG の概要

• エントリーDOI: 10.2210/pdb3lug/pdb
• 関連するPDBエントリー: 3luc 3lud 3luh 3luj 3luk
• 分子名称: Protein argonaute-2, PHOSPHATE ION, CYTIDINE-5'-MONOPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: mid domain, ribonucleoprotein, rna-binding, rna-mediated gene silencing, translation regulation, rna binding protein
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 47422.31

構造登録者

Frank, F.,Sonenberg, N.,Nagar, B. (登録日: 2010-02-17, 公開日: 2010-05-26, 最終更新日: 2024-02-21)

主引用文献

Frank, F.,Sonenberg, N.,Nagar, B.
Structural basis for 5'-nucleotide base-specific recognition of guide RNA by human AGO2.
Nature, 465:818-822, 2010

PubMed Abstract: MicroRNAs (miRNAs) mediate post-transcriptional gene regulation through association with Argonaute proteins (AGOs). Crystal structures of archaeal and bacterial homologues of AGOs have shown that the MID (middle) domain mediates the interaction with the phosphorylated 5' end of the miRNA guide strand and this interaction is thought to be independent of the identity of the 5' nucleotide in these systems. However, analysis of the known sequences of eukaryotic miRNAs and co-immunoprecipitation experiments indicate that there is a clear bias for U or A at the 5' position. Here we report the crystal structure of a MID domain from a eukaryotic AGO protein, human AGO2. The structure, in complex with nucleoside monophosphates (AMP, CMP, GMP, and UMP) mimicking the 5' end of miRNAs, shows that there are specific contacts made between the base of UMP or AMP and a rigid loop in the MID domain. Notably, the structure of the loop discriminates against CMP and GMP and dissociation constants calculated from NMR titration experiments confirm these results, showing that AMP (0.26 mM) and UMP (0.12 mM) bind with up to 30-fold higher affinity than either CMP (3.6 mM) or GMP (3.3 mM). This study provides structural evidence for nucleotide-specific interactions in the MID domain of eukaryotic AGO proteins and explains the observed preference for U or A at the 5' end of miRNAs.

PubMed: 20505670
DOI: 10.1038/nature09039

実験手法

X-RAY DIFFRACTION (1.849 Å)