Cahová, H. et al. Nature doi:10.1038/nature14020 (22 December 2014).

Some bacterial RNA was recently found to undergo covalent modification with nicotinamide adenine dinucleotide (NAD), but the function of this modification is not clear. Cahová et al. have now developed NAD captureSeq, a method to identify messages that bear this mark in the prokaryotic transcriptome. The method relies on chemical conversion of NAD to a moiety that can undergo copper-catalyzed cycloaddition, or 'click chemistry' with biotin azide, for subsequent enrichment with streptavidin beads and sequencing. The researchers found that NAD can stabilize transcripts analogously to the 5′ cap structure in eukaryotic cells. The mark is more prevalent in small regulatory RNAs, and the researchers were able to identify an enzyme with decapping activity.