Q5SMG8 · MGTE_THET8

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).

Catalytic activity

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).

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site59Mg2+ 1 (UniProtKB | ChEBI)
Binding site91Mg2+ 2 (UniProtKB | ChEBI)
Binding site95Mg2+ 3 (UniProtKB | ChEBI)
Binding site136Mg2+ 3 (UniProtKB | ChEBI)
Binding site170ATP (UniProtKB | ChEBI)
Binding site185ATP (UniProtKB | ChEBI)
Binding site187ATP (UniProtKB | ChEBI)
Binding site188ATP (UniProtKB | ChEBI)
Binding site207ATP (UniProtKB | ChEBI)
Binding site216Mg2+ 4 (UniProtKB | ChEBI)
Binding site223Mg2+ 5 (UniProtKB | ChEBI)
Binding site226Mg2+ 1 (UniProtKB | ChEBI)
Binding site226Mg2+ 5 (UniProtKB | ChEBI)
Binding site247Mg2+ 2 (UniProtKB | ChEBI)
Binding site250Mg2+ 5 (UniProtKB | ChEBI)
Binding site255Mg2+ 4 (UniProtKB | ChEBI)
Binding site258Mg2+ 6 (UniProtKB | ChEBI)
Binding site259Mg2+ 6 (UniProtKB | ChEBI)
Binding site275Ca2+ (UniProtKB | ChEBI)
Binding site275Mn2+ 1 (UniProtKB | ChEBI); inhibitor
Binding site304Mn2+ 2 (UniProtKB | ChEBI); inhibitor
Binding site307Mn2+ 2 (UniProtKB | ChEBI); inhibitor
Binding site311Ca2+ (UniProtKB | ChEBI)
Binding site311Mn2+ 1 (UniProtKB | ChEBI); inhibitor
Binding site383Mn2+ 2 (UniProtKB | ChEBI); inhibitor
Binding site418Mg2+ 6 (UniProtKB | ChEBI)
Binding site428Mg2+ 7 (UniProtKB | ChEBI)
Binding site432Mg2+ 7 (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentplasma membrane
Molecular Functionidentical protein binding
Molecular Functionmagnesium ion binding
Molecular Functionmagnesium ion transmembrane transporter activity
Molecular Functionprotein homodimerization activity
Biological Processmagnesium ion transport

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Magnesium transporter MgtE

Gene names

    • Name
      mgtE
    • Ordered locus names
      TTHA1060

Organism names

Accessions

  • Primary accession
    Q5SMG8

Proteomes

Subcellular Location

Cell inner membrane
; Multi-pass membrane protein

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain1-283Cytoplasmic
Transmembrane284-306Helical
Topological domain307-315Periplasmic
Transmembrane316-337Helical
Topological domain338-351Cytoplasmic
Transmembrane352-381Helical
Topological domain382-385Periplasmic
Transmembrane386-409Helical
Topological domain410-420Cytoplasmic
Transmembrane421-443Helical
Topological domain444-450Periplasmic

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis59Still possesses a slight channel activity.
Mutagenesis187Decreases ATP binding.
Mutagenesis226Abolishes the Mg2+-dependent suppression of the Mg2+ influx; when associated with A-250.
Mutagenesis227Cannot bind ATP.
Mutagenesis250Abolishes the Mg2+-dependent suppression of the Mg2+ influx; when associated with N-226.
Mutagenesis258Abolishes the Mg2+-dependent suppression of the Mg2+ influx.
Mutagenesis259Abolishes the Mg2+-dependent suppression of the Mg2+ influx.
Mutagenesis285Abolishes Mg2+-transport activity.
Mutagenesis304Does not affect Mg2+ transport, but increases permeability for Mn2+; when associated with A-307 and A-383.
Mutagenesis307Does not affect Mg2+ transport, but increases permeability for Mn2+; when associated with A-304 and A-383.
Mutagenesis311Does not affect Mg2+ transport, but increases permeability for Mn2+ and Ca2+.
Mutagenesis318Abolishes Mg2+-transport activity.
Mutagenesis321Abolishes Mg2+-transport activity.
Mutagenesis324Abolishes Mg2+-transport activity.
Mutagenesis325Loss of channel activity.
Mutagenesis328Loss of channel activity.
Mutagenesis329Abolishes Mg2+-transport activity.
Mutagenesis332Does not affect activity. Increases Ni2+ sensitivity.
Mutagenesis333Abolishes Mg2+-transport activity.
Mutagenesis359Abolishes Mg2+-transport activity.
Mutagenesis383Does not affect Mg2+ transport, but increases permeability for Mn2+; when associated with A-304 and A-307.
Mutagenesis424Does not affect activity. Increases Ni2+ sensitivity.
Mutagenesis432Abolishes Mg2+-transport activity.
Mutagenesis435Loss of channel activity.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00003638891-450Magnesium transporter MgtE

Interaction

Subunit

Homodimer.

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntact
BINARY Q5SMG8mgtE Q5SMG82EBI-15652583, EBI-15652583

Protein-protein interaction databases

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain138-200CBS 1
Domain202-258CBS 2

Sequence similarities

Belongs to the SLC41A transporter family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    450
  • Mass (Da)
    50,078
  • Last updated
    2004-12-21 v1
  • Checksum
    6F5930DCDDB90B05
MEEKLAVSLQEALQEGDTRALREVLEEIHPQDLLALWDELKGEHRYVVLTLLPKAKAAEVLSHLSPEEQAEYLKTLPPWRLREILEELSLDDLADALQAVRKEDPAYFQRLKDLLDPRTRAEVEALARYEEDEAGGLMTPEYVAVREGMTVEEVLRFLRRAAPDAETIYYIYVVDEKGRLKGVLSLRDLIVADPRTRVAEIMNPKVVYVRTDTDQEEVARLMADYDFTVLPVVDEEGRLVGIVTVDDVLDVLEAEATEDIHKLGAVDVPDLVYSEAGPVALWLARVRWLVILILTGMVTSSILQGFESVLEAVTALAFYVPVLLGTGGNTGNQSATLIIRALATRDLDLRDWRRVFLKEMGVGLLLGLTLSFLLVGKVYWDGHPLLLPVVGVSLVLIVFFANLVGAMLPFLLRRLGVDPALVSNPLVATLSDVTGLLIYLSVARLLLEAV

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AP008226
EMBL· GenBank· DDBJ
BAD70883.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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