K9UJK2 · TM175_CHAP6

Function

function

Potassium channel (PubMed:28723891).
The channel is permeable for K+, Rb+ and Cs+, while it is unable to conduct Na+ (PubMed:28723891).

Catalytic activity

Features

Showing features for site.

120320406080100120140160180200
TypeIDPosition(s)Description
Site23Hydrophobic filter residue 1
Site27Hydrophobic filter residue 2
Site30Hydrophobic filter residue 3

GO annotations

AspectTerm
Cellular Componentmembrane
Molecular Functionidentical protein binding
Molecular Functionpotassium channel activity
Molecular Functionproton channel activity
Biological Processpotassium ion transmembrane transport
Biological Processprotein homotetramerization

Keywords

Protein family/group databases

    • 1.A.78.2.10the k+-selective channel in endosomes and lysosomes (kel) family

Names & Taxonomy

Protein names

  • Recommended name
    Potassium channel Cha6605_3372
  • Alternative names
    • Transmembrane protein 175
      (CmTMEM175
      )

Gene names

    • ORF names
      Cha6605_3372

Organism names

Accessions

  • Primary accession
    K9UJK2

Proteomes

Subcellular Location

Membrane
; Multi-pass membrane protein

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain1-7Cytoplasmic
Transmembrane8-31Helical; Name=TM1
Topological domain32-52Extracellular
Transmembrane53-78Helical; Name=TM2
Topological domain79-84Cytoplasmic
Transmembrane85-110Helical; Name=TM3
Topological domain111-117Extracellular
Transmembrane118-142Helical; Name=TM4
Topological domain143-154Cytoplasmic
Transmembrane155-181Helical; Name=TM5
Topological domain182-183Extracellular
Transmembrane184-199Helical; Name=TM6
Topological domain200-203Cytoplasmic

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis23Impaired selectivity. Can conduct both K+ and Na+.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004420041-203Potassium channel Cha6605_3372

Interaction

Subunit

Homotetramer (PubMed:28723891).

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntact
BINARY K9UJK2Cha6605_3372 K9UJK22EBI-20710438, EBI-20710438

Protein-protein interaction databases

Family & Domains

Features

Showing features for motif, region.

TypeIDPosition(s)Description
Motif12-18RxxxFSD motif
Region37-42Short helix H1
Region44-50Short helix H2

Domain

In contrast to canonical tetrameric potassium channels, lacks the TVGYG selectivity filter motif and presents a completely different structure. The six transmembrane regions are tightly packed within each subunit without undergoing domain swapping. Transmembranes TM1-TM3 are positioned on the inner circle of the channel tetramer and participate in inter-subunit interactions that are central to the assembly of the ion conduction pore. The RxxxFSD motif within transmembrane TM1 coordinates a network of specific inter- and intra-subunit interactions with other conserved residues on TM2 and TM3 and plays a key role in the tetrameric assembly of the channel. Transmembrane TM4-TM6 are positioned on the periphery of the channel and do not contribute to contacts with neighboring subunits. Transmembranes TM1 and TM2 are linked by an extended strand-like tail and two short helices (H1 and H2) which protrude outwards from the main body of the transmembrane domain and enclose the external open entrance of the ion conduction pore in the channel tetramer. Transmembrane TM3 is bent into two segments (TM3a and TM3b) due to the presence of a conserved proline (Pro-102). Transmembrane TM1 forms the pore-lining inner helix at the center of the channel, creating an hourglass-shaped ion permeation pathway in the channel tetramer. Three hydrophobic residues (Ile-23, Leu-27 and Leu-30) on the C-terminal half of the TM1 helix form a bottleneck along the ion conduction pathway and serve as the selectivity filter of the channel. Ile-23 is probably responsible for channel selectivity.

Sequence similarities

Belongs to the TMEM175 family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    203
  • Mass (Da)
    22,674
  • Last updated
    2013-03-06 v1
  • Checksum
    53D7E93F759FEBE4
MVEAPEQSETGRIEAFSDGVFAIAITLLVLEIKVPQHKIVETVGLVSSLLSLWPSYLAFLTSFASILVMWVNHHRIFSLVARTDHAFFYWNGLLLMLVTFVPFPTALLAEYLIHPQARVAASVYAGIFLAIAIVFNRLWKHAATADRLLAQKADRHEVDAITKQYRFGPGLYLVAFALSFISVWLSVGVCFVLAIYFALRSNA

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP003600
EMBL· GenBank· DDBJ
AFY94374.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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