Figure 5.

Different modes of sncRNA function, using linear base pairing, 3D structure-based aptamer function, and a combination of both.A, complementarity to target sequence without protein binding. B, protein-assisted RNAi-based linear base pairing. C, binding with protein using a 3D structure as an aptamer. Note that the sncRNA can fold either on its own or multimerize with other RNAs to form higher-order structures for binding activity. D, combination of linear base pairing and aptamer-like function with different domains. For a single sncRNA, the listed functional modes might be interchangeable under different subcellular environments (e.g., cytoplasmic, nuclear, and mitochondrial) and induced by specific local factors. RNP, ribonucleoprotein; sncRNA, small noncoding RNA.