Q5SMG8 · MGTE_THET8
- ProteinMagnesium transporter MgtE
- GenemgtE
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids450 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Highly selective magnesium channel that plays an important role in Mg2+ homeostasis (PubMed:17700703, PubMed:19798051, PubMed:25367295, PubMed:33905418).
Functions as a Mg2+-dependent gating channel (PubMed:19798051, PubMed:25367295, PubMed:33905418).
Exhibits low activity with cobalt, suggesting that it might also be involved in the uptake of Co2+ as a micronutrient (PubMed:19798051).
Also exhibits low activity with Ca2+, but it shows almost no activity with Mn2+ (PubMed:25367295).
Functions as a Mg2+-dependent gating channel (PubMed:19798051, PubMed:25367295, PubMed:33905418).
Exhibits low activity with cobalt, suggesting that it might also be involved in the uptake of Co2+ as a micronutrient (PubMed:19798051).
Also exhibits low activity with Ca2+, but it shows almost no activity with Mn2+ (PubMed:25367295).
Catalytic activity
- Mg2+(in) = Mg2+(out)
Activity regulation
The channel activity is regulated via the N-terminal cytoplasmic region, which acts as a Mg2+ sensor to regulate the gating of the ion-conducting pore in response to the intracellular magnesium concentration (PubMed:19798051, PubMed:25367295, PubMed:33905418).
Under high-intracellular magnesium conditions, binding of magnesium to the N-terminal cytoplasmic domain stabilizes the closed conformation of the channel (PubMed:19798051, PubMed:25367295, PubMed:33905418).
Under low-intracellular magnesium conditions, the channel is in equilibrium between the open and closed states (PubMed:19798051).
A cation-binding site within the membrane (M1) strictly recognizes the size and geometry of the Mg2+ hydration shells, which may be important for the selective transport of Mg2+ over other cations (PubMed:25367295).
Cation-binding sites on the periplasmic side (M2 and M3) regulate channel opening and prevent conduction of near-cognate cations (PubMed:25367295).
Binding of Mn2+ to the periplasmic sites strongly inhibits the Mg2+ transport activity (PubMed:25367295).
In addition, activity is regulated by ATP, which binds to MgtE and modulates its Mg2+-dependent channel gating (PubMed:28747715).
ATP binding enhances the intracellular domain affinity for Mg2+ within physiological concentrations of this divalent cation, enabling MgtE to function as an in vivo Mg2+ sensor (PubMed:28747715).
ATP dissociation from MgtE upregulates Mg2+ influx at both high and low intracellular Mg2+ concentrations (PubMed:28747715).
Under high-intracellular magnesium conditions, binding of magnesium to the N-terminal cytoplasmic domain stabilizes the closed conformation of the channel (PubMed:19798051, PubMed:25367295, PubMed:33905418).
Under low-intracellular magnesium conditions, the channel is in equilibrium between the open and closed states (PubMed:19798051).
A cation-binding site within the membrane (M1) strictly recognizes the size and geometry of the Mg2+ hydration shells, which may be important for the selective transport of Mg2+ over other cations (PubMed:25367295).
Cation-binding sites on the periplasmic side (M2 and M3) regulate channel opening and prevent conduction of near-cognate cations (PubMed:25367295).
Binding of Mn2+ to the periplasmic sites strongly inhibits the Mg2+ transport activity (PubMed:25367295).
In addition, activity is regulated by ATP, which binds to MgtE and modulates its Mg2+-dependent channel gating (PubMed:28747715).
ATP binding enhances the intracellular domain affinity for Mg2+ within physiological concentrations of this divalent cation, enabling MgtE to function as an in vivo Mg2+ sensor (PubMed:28747715).
ATP dissociation from MgtE upregulates Mg2+ influx at both high and low intracellular Mg2+ concentrations (PubMed:28747715).
Features
Showing features for binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 59 | Mg2+ 1 (UniProtKB | ChEBI) | |||
Binding site | 91 | Mg2+ 2 (UniProtKB | ChEBI) | |||
Binding site | 95 | Mg2+ 3 (UniProtKB | ChEBI) | |||
Binding site | 136 | Mg2+ 3 (UniProtKB | ChEBI) | |||
Binding site | 170 | ATP (UniProtKB | ChEBI) | |||
Binding site | 185 | ATP (UniProtKB | ChEBI) | |||
Binding site | 187 | ATP (UniProtKB | ChEBI) | |||
Binding site | 188 | ATP (UniProtKB | ChEBI) | |||
Binding site | 207 | ATP (UniProtKB | ChEBI) | |||
Binding site | 216 | Mg2+ 4 (UniProtKB | ChEBI) | |||
Binding site | 223 | Mg2+ 5 (UniProtKB | ChEBI) | |||
Binding site | 226 | Mg2+ 1 (UniProtKB | ChEBI) | |||
Binding site | 226 | Mg2+ 5 (UniProtKB | ChEBI) | |||
Binding site | 247 | Mg2+ 2 (UniProtKB | ChEBI) | |||
Binding site | 250 | Mg2+ 5 (UniProtKB | ChEBI) | |||
Binding site | 255 | Mg2+ 4 (UniProtKB | ChEBI) | |||
Binding site | 258 | Mg2+ 6 (UniProtKB | ChEBI) | |||
Binding site | 259 | Mg2+ 6 (UniProtKB | ChEBI) | |||
Binding site | 275 | Ca2+ (UniProtKB | ChEBI) | |||
Binding site | 275 | Mn2+ 1 (UniProtKB | ChEBI); inhibitor | |||
Binding site | 304 | Mn2+ 2 (UniProtKB | ChEBI); inhibitor | |||
Binding site | 307 | Mn2+ 2 (UniProtKB | ChEBI); inhibitor | |||
Binding site | 311 | Ca2+ (UniProtKB | ChEBI) | |||
Binding site | 311 | Mn2+ 1 (UniProtKB | ChEBI); inhibitor | |||
Binding site | 383 | Mn2+ 2 (UniProtKB | ChEBI); inhibitor | |||
Binding site | 418 | Mg2+ 6 (UniProtKB | ChEBI) | |||
Binding site | 428 | Mg2+ 7 (UniProtKB | ChEBI) | |||
Binding site | 432 | Mg2+ 7 (UniProtKB | ChEBI) | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | plasma membrane | |
Molecular Function | identical protein binding | |
Molecular Function | magnesium ion binding | |
Molecular Function | magnesium ion transmembrane transporter activity | |
Molecular Function | protein homodimerization activity | |
Biological Process | magnesium ion transport |
Keywords
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameMagnesium transporter MgtE
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Deinococcota > Deinococci > Thermales > Thermaceae > Thermus
Accessions
- Primary accessionQ5SMG8
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Cell inner membrane ; Multi-pass membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Topological domain | 1-283 | Cytoplasmic | |||
Transmembrane | 284-306 | Helical | |||
Topological domain | 307-315 | Periplasmic | |||
Transmembrane | 316-337 | Helical | |||
Topological domain | 338-351 | Cytoplasmic | |||
Transmembrane | 352-381 | Helical | |||
Topological domain | 382-385 | Periplasmic | |||
Transmembrane | 386-409 | Helical | |||
Topological domain | 410-420 | Cytoplasmic | |||
Transmembrane | 421-443 | Helical | |||
Topological domain | 444-450 | Periplasmic | |||
Keywords
- Cellular component
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Mutagenesis | 59 | Still possesses a slight channel activity. | |||
Mutagenesis | 187 | Decreases ATP binding. | |||
Mutagenesis | 226 | Abolishes the Mg2+-dependent suppression of the Mg2+ influx; when associated with A-250. | |||
Mutagenesis | 227 | Cannot bind ATP. | |||
Mutagenesis | 250 | Abolishes the Mg2+-dependent suppression of the Mg2+ influx; when associated with N-226. | |||
Mutagenesis | 258 | Abolishes the Mg2+-dependent suppression of the Mg2+ influx. | |||
Mutagenesis | 259 | Abolishes the Mg2+-dependent suppression of the Mg2+ influx. | |||
Mutagenesis | 285 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 304 | Does not affect Mg2+ transport, but increases permeability for Mn2+; when associated with A-307 and A-383. | |||
Mutagenesis | 307 | Does not affect Mg2+ transport, but increases permeability for Mn2+; when associated with A-304 and A-383. | |||
Mutagenesis | 311 | Does not affect Mg2+ transport, but increases permeability for Mn2+ and Ca2+. | |||
Mutagenesis | 318 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 321 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 324 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 325 | Loss of channel activity. | |||
Mutagenesis | 328 | Loss of channel activity. | |||
Mutagenesis | 329 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 332 | Does not affect activity. Increases Ni2+ sensitivity. | |||
Mutagenesis | 333 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 359 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 383 | Does not affect Mg2+ transport, but increases permeability for Mn2+; when associated with A-304 and A-307. | |||
Mutagenesis | 424 | Does not affect activity. Increases Ni2+ sensitivity. | |||
Mutagenesis | 432 | Abolishes Mg2+-transport activity. | |||
Mutagenesis | 435 | Loss of channel activity. | |||
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000363889 | 1-450 | Magnesium transporter MgtE | ||
Interaction
Subunit
Homodimer.
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | IntAct | |
---|---|---|---|---|---|
BINARY | Q5SMG8 | mgtE Q5SMG8 | 2 | EBI-15652583, EBI-15652583 |
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Domain | 138-200 | CBS 1 | |||
Domain | 202-258 | CBS 2 | |||
Sequence similarities
Belongs to the SLC41A transporter family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length450
- Mass (Da)50,078
- Last updated2004-12-21 v1
- Checksum6F5930DCDDB90B05
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AP008226 EMBL· GenBank· DDBJ | BAD70883.1 EMBL· GenBank· DDBJ | Genomic DNA |