Protein: Protein TonB (P02929)
Organism: Escherichia coli (strain K12)
Function: Interacts with outer membrane receptor proteins that carry out high-affinity binding and energy dependent uptake into the periplasmic space of specific substrates such as cobalamin, and various iron compounds (such as iron dicitrate, enterochelin, aerobactin, etc.). In the absence of TonB these receptors bind their substrates but do not carry out active transport. TonB also interacts with some colicins and is involved in the energy-dependent, irreversible steps of bacteriophages phi 80 and T1 infection. It could act to transduce energy from the cytoplasmic membrane to specific energy-requiring processes in the outer membrane, resulting in the release into the periplasm of ligands bound by these outer membrane proteins. Implicated in hydroxy radical-mediated cell death induced by hydroxyurea treatment.
Subcellular location: Cell inner membrane; Single-pass membrane protein; Periplasmic side.
Sequence: MTLDLPRRFPWPTLLSVCIHGAVVAGLLYTSVHQVIELPAPAQPISVTMVTPADLEPPQAVQPPPEPVVEPEPEPEPIPEPPKEAPVVIEKPKPKPKPKPKPVKKVQEQPKRDVKPVESRPASPFENTAPARLTSSTATAATSKPVTSVASGPRALSRNQPQYPARAQALRIEGQVKVKFDVTPDGRVDNVQILSAKPANMFEREVKNAMRRWRYEPGKPGSGIVVNILFKINGTTEIQ
InterPro domains: - IPR003538: Gram-negative bacterial TonB protein (family) [91-212]
- IPR049924: TonB, proline-rich region (domain) [33-157]
- IPR006260: TonB/TolA, C-terminal (domain) [161-233]
- IPR051045: TonB-dependent transporter energy transducer (family) [8-222]
- IPR037682: TonB, C-terminal (domain) [148-239]
Interaction partners: - Biopolymer transport protein ExbD
- Biopolymer transport protein ExbB
- Vitamin B12 transporter BtuB
- Ferrichrome outer membrane transporter/phage receptor
- Ferrienterobactin receptor
- Fe
- Hydroxamate siderophore receptor FhuE
- Outer membrane porin PhoE
- Catecholate siderophore receptor Fiu
- Translation initiation factor IF-2
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0003824 (catalytic activity), GO:0005488 (binding), GO:0036094 (small molecule binding), GO:0097159 (organic cyclic compound binding), GO:1901363 (heterocyclic compound binding), GO:0016787 (hydrolase activity), GO:0043167 (ion binding), GO:0097367 (carbohydrate derivative binding), GO:0005515 (protein binding), GO:0016817 (hydrolase activity, acting on acid anhydrides), GO:1901265 (nucleoside phosphate binding), GO:0043168 (anion binding), GO:0042802 (identical protein binding), GO:0043169 (cation binding), GO:0000166 (nucleotide binding), GO:0032553 (ribonucleotide binding), GO:0017076 (purine nucleotide binding), GO:0035639 (purine ribonucleoside triphosphate binding), GO:0019003 (GDP binding), GO:0032555 (purine ribonucleotide binding), GO:0016818 (hydrolase activity, acting on acid anhydrides, in phosphorus-containing anhydrides), GO:0046872 (metal ion binding), GO:0016462 (pyrophosphatase activity), GO:0005525 (GTP binding), GO:0019001 (guanyl nucleotide binding), GO:0000287 (magnesium ion binding), GO:0032561 (guanyl ribonucleotide binding), GO:0017111 (ribonucleoside triphosphate phosphatase activity), GO:0003924 (GTPase activity)
Biological Process (BP): GO:0008150 (biological process), GO:0050896 (response to stimulus), GO:0009987 (cellular process), GO:0051716 (cellular response to stimulus), GO:0006950 (response to stress), GO:0033554 (cellular response to stress), GO:0006974 (cellular response to DNA damage stimulus)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0098552 (side of membrane), GO:0009986 (cell surface), GO:0071944 (cell periphery), GO:0016020 (membrane), GO:0009897 (external side of plasma membrane), GO:0005886 (plasma membrane)