Crystal structure of the MID-PIWI lobe of a eukaryotic Argonaute protein.

ABSTRACT: Argonaute proteins (AGOs) are essential effectors in RNA-mediated gene silencing pathways. They are characterized by a bilobal architecture, in which one lobe contains the N-terminal and PAZ domains and the other contains the MID and PIWI domains. Here, we present the first crystal structure of the MID-PIWI lobe from a eukaryotic AGO, the Neurospora crassa QDE-2 protein. Compared to prokaryotic AGOs, the domain orientation is conserved, indicating a conserved mode of nucleic acid binding. The PIWI domain shows an adaptable surface loop next to a eukaryote-specific α-helical insertion, which are both likely to contact the PAZ domain in a conformation-dependent manner to sense the functional state of the protein. The MID-PIWI interface is hydrophilic and buries residues that were previously

SUBMITTER: Boland A 

PROVIDER: S-EPMC3127882 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature