NAD captureSeq was employed to identify NAD-RNAs in Sulfolobus acidocaldarius and Haloferax volcanii

The absence of 5?? capped RNAs was an essential hallmark of the many unique features of prokaryotic gene expression. In the past decade, the detection of nicotinamide adenine dinucleotide (NAD+) and derivatives of Coenzyme A (CoA) linked to the 5??-end of bacterial RNAs challenged this scenario (1). NAD-RNAs were detected in Bacteria (Escherichia coli, Staphylococcus aureus, and Bacillus subtillis), while in Eukaryotes, they were found in Humans, Saccharomyces cerevisiae, Arabidopsis thaliana, and the mitochondria of yeast and human cells. While the biological consequences of NAD-capping in bacteria and eukaryotes are slowly coming to light, there is no similar knowledge for this process in Archaea. Here, we evaluate NAD-capping's presence and biological relevance in Archaea, focusing on the hyperthermophile S. acidocaldarius.