Apparent Horizontal Transfer of Eukaryotic and Archaeal aaRS Genes into Different Bacterial Lineages
| Bacterial group | Horizontally transferred aaRS genes | Source |
| Spirochetes | Pro (Borrelia only), Ile, Met, Arg, His, Asn | eukaryotic |
| Ser, Glu | eukaryotic mitochondrial | |
| Lys-I, Phe α–β | archaeal | |
| Gly-1 | eukaryotic or archaeal | |
| Lys-II (Treponema only) | bacterial (γ-Proteobacteria?) | |
| Chlamydia | Ile, Met, Arg, Asn?? | eukaryotic |
| Glu | eukaryotic mitochondrial | |
| Mycobacteria | Ile, Asn?? | eukaryotic |
| Ser, Gly(1) | eukaryotic or archaeal | |
| Mycoplasmas | Pro, Asn | eukaryotic |
| Gly(1) | eukaryotic or archaeal | |
| γ-Proteobacteria | Asn, Gln | eukaryotic |
| Met | archaeal(?) | |
| Helicobacter | His | eukaryotic |
| Cyanobacteria | Arg, Asn | eukaryotic |
| His (2nd form, no displacement) | archaeal | |
| Bacillus | Asn | eukaryotic |
| His (2nd form, no displacement) | archaeal | |
| Aquifex | His (2nd form, no displacement) | archaeal |