rRNAbound

rRNAbound is a term used in molecular biology to describe complexes in which ribosomal RNA (rRNA) is bound by proteins or other molecules. It encompasses the mature ribosome as well as transient ribonucleoprotein assemblies that participate in rRNA processing, folding, modification, and the regulation of translation. The concept emphasizes the central role of rRNA as a structural and catalytic core of ribonucleoprotein machines.

Binding patterns and domains are central to rRNAbound interactions. rRNA binding is mediated by protein domains and RNA motifs, with contacts ranging from electrostatic interactions with the RNA backbone to base-specific contacts with helices and bulges. Proteins such as ribosomal proteins and assembly factors often harbor RNA-binding motifs that recognize conserved rRNA structures, while small nucleolar RNAs and guide RNAs can direct chemical modifications by forming rRNAbound ribonucleoproteins.

Biological roles of rRNAbound complexes include participation in ribosome assembly, quality control, and the regulation of translational fidelity. In eukaryotes, snoRNPs and other rRNA-binding factors direct modifications such as 2'-O-methylation and pseudouridylation during rRNA maturation, helping to ensure proper ribosome function. Across organisms, rRNAbound interactions contribute to the folding and stabilization of rRNA within ribosomal subunits.

Research and significance: studying rRNAbound states aids understanding of ribosome biogenesis, translational regulation, and the impact of ribosome dysfunction on health and disease. Techniques such as cryo-electron microscopy, crosslinking approaches, and RNA–protein interaction assays are used to identify binding partners and map contact points within these complexes.

Terminology and scope: rRNAbound is a descriptive label used in reviews and datasets to group studies focused on interactions between rRNA and binding partners; it is not a formal taxonomic category.