Table 2.

Biological functions of diribonucleotides.

Nucleotide	Function	References
pGpG	1. Feedback inhibition of c-di-GMP phosphodiesterases 2. Nanopriming of transcripts	(Cohen et al. 2015, Orr et al. 2015) (Druzhinin et al. 2015)
pApA	1. Feedback inhibition of c-di-AMP phosphodiesterases	(Bowman et al. 2016)
pUpA	1. Nanopriming of transcripts	(Druzhinin et al. 2015, Vvedenskaya et al. 2012)
NAD/NAD+	1. Cellular metabolism 2. Nanopriming of transcripts	(Bird et al. 2016) (Vvedenskaya and Nickels 2020)
FAD	1. Cellular metabolism 2. Nanopriming of transcripts	(Vvedenskaya and Nickels 2020)