Fig. 2
From: MicroRNA clustering on the biogenesis of suboptimal microRNAs
Cluster assistance between miR-144 and miR-451. miR-451 is a poor substrate for Microprocessor due to its suboptimal structural features. Therefore, it is not expressed abundantly when it exists alone. However, in actual cells, miR-451 is known to be processed efficiently by Microprocessor and is highly expressed. This is due to “cluster assistance” between miR-451 and its neighboring miRNA, miR-144. The existence of this helper hairpin (miR-144) enables the recipient hairpin (miR-451) to be recognized and processed by Microprocessor