Cover image

Human argonaute microRNA complex (PDB id: 8D71; Xiao Y, Liu TM, MacRae IJ. 2023. A tiny loop in the Argonaute PIWI domain tunes small RNA seed strength. EMBO Rep 24: e55806). Argonaute proteins use microRNAs (miRNAs) and small interfering RNAs (siRNAs) as guides to regulate gene expression in plants and animals. Human argonaute is shown in this structure to recognize a short region (6–8 nt) of miRNA. microRNA backbone is displayed in NDB colors: A—red, G—green, U—cyan; argonaute protein is displayed as a wheat-colored ribbon. Missing RNA and protein segments are indicated by dotted lines. Cover image provided by the Nucleic Acid Knowledgebase (nakb.org). Image generated using ChimeraX (Protein Sci 30: 70–82).