TABLE 3.

Phyletic distribution of seven TA families in 218 prokaryotic genomesa

OrganismNo. of indicated loci Total
relBEbparDEvapBChicABmazEFphd-docccdAB
Bacteria369913529111739101,069
Archaea31020828230272
Total4009156011911942101,341
Stand alone202212374080
  • a Gene loci were divided into gene families based on sequence similarities between the toxins. Note that hicAB loci have a reversed gene order (toxin gene upstream of antitoxin gene).

  • b The RelE toxin family includes the HigB, YhaV, YoeB, and YafQ subfamilies that all share weak but significant sequence similarity and may have similar tertiary folds (21, 41).