| T4SE classification schemes |
|
Various pathogenic bacteria and symbionts use T4SSs to deliver effector proteins or DNA–protein complexes into their host
(either eukaryotic target cells or protozoan hosts). The T4SSs can either inject their effectors directly into the host cell or secrete them into the
medium, thereby exerting remarkably different effects on host cell functions during infection [Grohmann E, et al (2018) Mol Microbiol]. Grohmann E, et al classified T4SEs which are deliverd into eukaryotic target cells five types: 1. Effector proteins injected into eukaryotic target cells, such as effectors of Helicobacter, Bartonella, Anaplasma and Ehrlichia. 2. Genes transferred to host cells, such as effectors of Agrobacterium and Bartonella. 3. Effectors involved in intracellular survival of symbionts, such as effectors of Wolbachia and Mesorhizobium. 4. Effectors involved in intracellular survival of pathogens, such as effectors of Legionella, Coxiella, Bartonella, Brucella and Rickettsia. 5. Effectors involved in toxin secreted to eukaryotic target cell, such as Bordetella. 6. Effectors involved in toxin delivered to bacteria, such as Xanthomonas. Here, we classify collected verified T4SEs into these groups, and the T4SEs which is uncertain are classified into 'Undetermined'. |
| Classification of T4SEs (Click on the types to view members) |
| Group | Classification | Number | Genus |
1 |
Effector proteins injected into eukaryotic target cells | 17 |
Helicobacter, Anaplasma and Ehrlichia |
2 |
Genes transferred to host cells | 20 |
Agrobacterium |
3 |
Effectors involved in intracellular survival of symbionts | 15 |
Wolbachia |
4 |
Effectors involved in intracellular survival of pathogens | 472 |
Legionella, Coxiella, Brucella and Rickettsia |
5 |
Effectors involved in toxin secreted to eukaryotic target cell | 5 |
Bordetella |
6 |
Effectors involved in toxin delivered to bacteria | 1 |
Xanthomonas |
7 |
Undetermined | 10 |
Bartonella, Stenotrophomonas, and Streptococcus |
