Abstract 1754 Metabolic Fates of Co-enzymes Capped RNA

Although cellular RNA polymerases are now known to initiate RNA synthesis with nicotinamide adenine dinucleotide (NAD) and similar coenzymes, the biological role of these atypical RNA caps is still unknown. Such unusual caps might modulate RNA function, or enzymes previously shown to use NAD+ might react instead with capped RNA. For example, the T4 phage ModB ADP-ribosyl transferase was recently shown to use NAD-capped RNA to add RNA to proteins (Wolfram-Schauerte et al., 2024, Nature). Most enzymes that use NAD catalyze redox reactions using oxidized NAD to accept electrons or catalyze the transfer AMP, or ADP-ribose, from NAD to other compounds.