Synthesis and degradation of the cyclic dinucleotide messenger c‐di‐AMP in the hyperthermophilic archaeon Pyrococcus yayanosii

Abstract

AbstractCyclic di‐adenosine monophosphate (c‐di‐AMP) is a newly identified prokaryotic cyclic dinucleotide second messenger well elucidated in bacteria, while less studied in archaea. Here, we describe the enzymes involved in c‐di‐AMP metabolism in the hyperthermophilic archaeon Pyrococcus yayanosii. Our results demonstrate that c‐di‐AMP is synthesized from two molecules of ATP by diadenylate cyclase (DAC) and degraded into pApA and then to AMP by a DHH family phosphodiesterase (PDE). DAC can be activated by a wider variety of ions, using two conserved residues, D188 and E244, to coordinate divalent metal ions, which is different from bacterial CdaA and DisA. PDE possesses a broad substrate spectrum like bacterial DHH family PDEs but shows a stricter base selection between A and G in cyclic dinucleotides hydrolysis. PDE shows differences in substrate binding patches from bacterial counterparts. C‐di‐AMP was confirmed to exist in Thermococcus kodakarensis cells, and the deletion of the dac or pde gene supports that the synthesis and degradation of c‐di‐AMP are catalyzed by DAC and PDE, respectively. Our results provide a further understanding of the metabolism of c‐di‐AMP in archaea.