[5] These small RNAs are predicted to fold into a conserved stem formed by the RNA's 3′ and 5′ ends and characterized by a single bulged cytosine, which are the known requirements for Ro binding.

[3] Biochemical fractionation and reconstitution experiments have established a functional requirement of human Y RNAs for chromosomal DNA replication in isolated vertebrate cell nuclei in vitro[3] and specific degradation of human Y RNAs inhibits DNA replication in vitro, and in intact cells in vivo.

[3] Y RNA function is thought to be mediated via interactions with chromatin and initiation proteins (including the origin recognition complex)[4] Y RNAs are overexpressed in some human tumours and are required for cell proliferation[12] and small, microRNA-sized breakdown products may be involved in autoimmunity and other pathological conditions.

[18][19] The radiation-resistant bacterium Deinococcus radiodurans encodes a homolog of Ro called rsr ("Ro sixty related"), and at least four small RNAs accumulate in Deinococcus under conditions where rsr expression is induced (UV irradiation); one of these RNAs appears to be a Y RNA homolog.

This role could be conserved, as Rsr and ncRNAs called YrlA and YrlB (Y RNA like) also associate with PNPase in an evolutionary distant bacterium Salmonella Typhimurium.