TABLE 2.
Features of select type I toxins in Gram-positive and Gram-negative bacteria
| Toxin | Length(amino acids) | Antitoxin RNA | Localization | Cellular effects (biological function) | Species (location) | References |
|---|---|---|---|---|---|---|
| Gram-positive | ||||||
| BsrE | 30 | SR5 | Membrane | Cell lysis (prophage stabilization?) | Bacillus subtilis (P6 prophage-like element) | (61, 130, 131) |
| BsrG | 38 | SR4 | Membrane | Delocalization of cell wall systhesis machinery, membrane invaginations, cell lysis (prophage stabilization?) | Bacillus subtilis (SPβ prophage) | (19, 131, 132) |
| CD | 34–47 | RCd | Membrane | Growth inhibition (prophage stabilization) | Clostridioides difficile (phiCD630 prophage) | (133, 134) |
| Fst | 33 | RNAII | Membrane | Nucleoid condensation, cell division defects (plasmid stabilization) | Enterococcus faecalis (plasmid pAD1) | (47, 55, 135) |
| PepA1 (SprA1) | 30 | SprA1AS | Membrane | Membrane permeabilization, cytolytic activity (altruistic cell death?) | Staphylococcus aureus (pathogenicity island) | (87, 88) |
| PepA2 (SprA2) | 35 | SprA2AS | Membrane | Membrane permeabilization, cytolytic activity (altruistic cell death?) | Staphylococcus aureus (chromosome) | (89) |
| PepG1 (SprG1) | 31, 44 | SprF1 | Membrane | Membrane permeabilization, cytolytic activity (altruistic cell death?) | Staphylococcus aureus (pathogenicity island) | (136) |
| TxpA | 59 | RatA | Membrane | Cell lysis (prophage stabilization?) | Bacillus subtilis (Skin prophage) | (24, 25) |
| YonT | 58 | SR6 | Membrane | Cell lysis (prophage stabilization?) | Bacillus subtilis (SPβ prophage) | (62, 137) |
| Gram-negative | ||||||
| AapA1 | 30 | IsoA1 | Inner membrane | Morphological changes, coccoid formation | Helicobacter pylori (chromosome) | (97) |
| DinQ | 27 | AgrB | Inner membrane | Depolarization, ATP drop, nucleoid condensation (persistence?) | Escherichia coli (chromosome) | (20) |
| Hok | 52 | Sok | Inner membrane | Depolarization, cellular leakage, ghost cell formation (plasmid stabilization) | Escherichia coli (plasmid R1) | (43, 44) |
| HokB | 49 | SokB | Inner membrane | Pore formation, depolarization, ATP efflux (persistence) | Escherichia coli (chromosome) | (7, 50, 138) |
| IbsC | 18 | SibC | Inner membrane | Depolarization | Escherichia coli (chromosome) | (15) |
| LdrD | 35 | RdlD | Inner membrane | Nucleoid condensation, inhibition of translation | Escherichia coli (chromosome) | (58, 139) |
| ShoB | 26 | OhsC | Inner membrane | Depolarization | Escherichia coli (chromosome) | (15) |
| TimP | 38 | TimR | Inner membrane | Leaky membrane | Salmonella enterica (chromosome) | (60) |
| TisB | 29 | IstR-1 | Inner membrane | Pore formation, depolarization, ATP drop, protection from aminoglycosides (persistence) | Escherichia coli (chromosome) | (6, 22, 140–143) |
| ZorO | 29 | OrzO | Inner membrane | Depolarization, ATP drop, protection from aminoglycosides (persistence?) | Escherichia coli (chromosome) | (103, 104, 144) |
| RalR | 64 | RalA | Cytoplasm | DNA cleavage | Escherichia coli (cryptic prophage rac) | (70) |
| SymE | 113 | SymR | Cytoplasm | RNA cleavage, nucleoid condensation | Escherichia coli (chromosome) | (72, 145) |