Purine-rich low complexity regions are potential RNA binding hubs in the human genome.

Many long noncoding RNAs are bound to chromatin. MEG3 binds to multiple different genomic locations, containing GA-rich motifs, and form RNA-DNA triplex structures. In this work, we test whether the MEG3 binding sites are specific enough to be regulated by a particular lncRNA. We show that at least in the case of MEG3, a subset of the triplex target sites (TTS) is able to hybridize with various different RNAs almost irrespectively of their sequences. Nowadays, the role of chromatin bound RNAs in the formation of 3D chromatin structure is actively discussed. We speculate that such universal TTSs may contribute to establishing long-distance chromosomal contacts.