Table 1.
Comparison of c-di-AMP- and c-di-GMP-mediated signaling
| c-di-GMP | c-di-AMP | |
|---|---|---|
| Discovery year | 1987 | 2008 |
| Chemical properties | ||
| Structural formula | C20H24N10O14P2 | C20H24N10O12P2 |
| Molecular weight | 690.4 Da | 658.4 Da |
| PDB structure code | C2E (95 structures) | 2BA (33 structures) |
| Oligomeric structure | Monomer, dimer (tetramer) | Monomer (dimer) |
| Intracellular levelsa | 0.1–10 μM | 0.5–18.8 μM |
| Turnover enzymes: gene and domain namesb, structures | ||
| Synthetase(cyclase) : | DgcA, AdrA GGDEF domain (PF00990, PDB: 1W25b) |
DisA, CdaA, CdaS, CdaM, CdaZ DisA_N (DAC) domain (PF02457, PDB: 3C1Y) |
| Hydrolase class I | YhjH, YkuI, BlrP1 EAL domain (PF00563, PDB: 2R6O) |
GdpP/PdeA, DhhP, DHH and DHHA1 domains (PF01388/PF02272, PDB: 5XSN) |
| Hydrolase class II | RpfG, PmGH, TM0186 HD-GYP domain (COG2206, PDB: 4R8Z) |
PgpH HDc domain (PF01966, PDB: 4S1B) |
| Receptor types | ||
| Riboswitches | Class I (PDB: 3IRW), Class II (PDB:3Q3Z) | YdaO (PDB: 4QLN) |
| Bacterial proteinsa | ||
| Widespread c-di-NMP-binding domains | PilZ domain (PF07238, PDB: 1YWU) | RCK_C domain (PF02080, PDB: 4XTT) |
| MshEN domain (PDB: 5HTL) | CBS domain pair (PDB: 5KS7) | |
| Histidine kinases | CckA, HATPase domain (PDB: 5IDM) | KdpD, USP-like domain (PDB: 2R8R) |
| Transcriptional regulators | BldD (PDB: 5KHD); FleQ (PDB: 5EXX) | BusR (RCK_C domain); DarR (COG4977) |
| Eukaryotic proteins | STING (PDB: 4EMT) | STING (PDB: 6CFF) |
| DDX41 (PDB: 5GVR) | RECON (PDB: 5UXF) | |
| Phylogenetic distribution | All bacterial phyla, Dictyostelium | Most bacterial phyla, Euryarchaeota |
| Regulated processes | Transcription, protein and polysaccharide secretion, motility, cell development, biofilm formation | DNA repair, sporulation, K+ transport, osmotic homeostasis, central metabolism, biofilm formation |