Table 1.

Concentration of (putative) nucleotide-based messengers detected in Braun et al. (2021) after nucleotide extraction and mass spectrometry, converted to micromolar concentrations assuming a cytosolic content of 200 mg/mL (Ray et al. 2015).

Organims	Haloferax volcanii		Sulfolobus acidocaldarius
Molecule	Levels during exponential growth (µM)	Levels during stationary growth (µM)	Levels during exponential growth (µM)	Levels during stationary growth (µM)
3′,5′-cCMP	0.52	0.13	n.d.	n.d.
3′,5′-cUMP	0.38	0.20	n.d.	n.d.
2′,3′-cAMP	30	20	1.0	0.69
2′,3′-cGMP	22	13	0.56	0.52
2′,3′-cCMP	15	11	0.22	0.32
2′,3′-cUMP	0.51	0.40	n.d.	≤ 0.02
3′,5′-c-di-AMP	8.2	9.1	n.d.	n.d.
5′-pApA	≤ 0.6	0.22	n.d.	≥ 0
Ap4A	1.9	0.29	125	8.1

n.d., not detected.