TM175_CHAP6
ID TM175_CHAP6 Reviewed; 203 AA.
AC K9UJK2;
DT 25-OCT-2017, integrated into UniProtKB/Swiss-Prot.
DT 06-MAR-2013, sequence version 1.
DT 25-MAY-2022, entry version 37.
DE RecName: Full=Potassium channel Cha6605_3372 {ECO:0000305};
DE AltName: Full=Transmembrane protein 175 {ECO:0000303|PubMed:28723891};
DE Short=CmTMEM175 {ECO:0000303|PubMed:28723891};
GN ORFNames=Cha6605_3372 {ECO:0000312|EMBL:AFY94374.1};
OS Chamaesiphon minutus (strain ATCC 27169 / PCC 6605).
OC Bacteria; Cyanobacteria; Synechococcales; Chamaesiphonaceae; Chamaesiphon.
OX NCBI_TaxID=1173020;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 27169 / PCC 6605;
RG US DOE Joint Genome Institute;
RA Gugger M., Coursin T., Rippka R., Tandeau De Marsac N., Huntemann M.,
RA Wei C.-L., Han J., Detter J.C., Han C., Tapia R., Chen A., Kyrpides N.,
RA Mavromatis K., Markowitz V., Szeto E., Ivanova N., Pagani I., Pati A.,
RA Goodwin L., Nordberg H.P., Cantor M.N., Hua S.X., Woyke T., Kerfeld C.A.;
RT "Finished chromosome of genome of Chamaesiphon sp. PCC 6605.";
RL Submitted (MAY-2012) to the EMBL/GenBank/DDBJ databases.
RN [2]
RP X-RAY CRYSTALLOGRAPHY (3.3 ANGSTROMS) OF 7-203, FUNCTION, TOPOLOGY,
RP SUBUNIT, DOMAIN, AND MUTAGENESIS OF ILE-23.
RX PubMed=28723891; DOI=10.1038/nature23269;
RA Lee C., Guo J., Zeng W., Kim S., She J., Cang C., Ren D., Jiang Y.;
RT "The lysosomal potassium channel TMEM175 adopts a novel tetrameric
RT architecture.";
RL Nature 547:472-475(2017).
CC -!- FUNCTION: Potassium channel (PubMed:28723891). The channel is permeable
CC for K(+), Rb(+) and Cs(+), while it is unable to conduct Na(+)
CC (PubMed:28723891). {ECO:0000269|PubMed:28723891}.
CC -!- SUBUNIT: Homotetramer (PubMed:28723891). {ECO:0000269|PubMed:28723891}.
CC -!- INTERACTION:
CC K9UJK2; K9UJK2: Cha6605_3372; NbExp=2; IntAct=EBI-20710438, EBI-20710438;
CC -!- SUBCELLULAR LOCATION: Membrane {ECO:0000255}; Multi-pass membrane
CC protein {ECO:0000269|PubMed:28723891}.
CC -!- DOMAIN: In contrast to canonical tetrameric potassium channels, lacks
CC the TVGYG selectivity filter motif and presents a completely different
CC structure. The six transmembrane regions are tightly packed within each
CC subunit without undergoing domain swapping. Transmembranes TM1-TM3 are
CC positioned on the inner circle of the channel tetramer and participate
CC in inter-subunit interactions that are central to the assembly of the
CC ion conduction pore. The RxxxFSD motif within transmembrane TM1
CC coordinates a network of specific inter- and intra-subunit interactions
CC with other conserved residues on TM2 and TM3 and plays a key role in
CC the tetrameric assembly of the channel. Transmembrane TM4-TM6 are
CC positioned on the periphery of the channel and do not contribute to
CC contacts with neighboring subunits. Transmembranes TM1 and TM2 are
CC linked by an extended strand-like tail and two short helices (H1 and
CC H2) which protrude outwards from the main body of the transmembrane
CC domain and enclose the external open entrance of the ion conduction
CC pore in the channel tetramer. Transmembrane TM3 is bent into two
CC segments (TM3a and TM3b) due to the presence of a conserved proline
CC (Pro-102). Transmembrane TM1 forms the pore-lining inner helix at the
CC center of the channel, creating an hourglass-shaped ion permeation
CC pathway in the channel tetramer. Three hydrophobic residues (Ile-23,
CC Leu-27 and Leu-30) on the C-terminal half of the TM1 helix form a
CC bottleneck along the ion conduction pathway and serve as the
CC selectivity filter of the channel. Ile-23 is probably responsible for
CC channel selectivity. {ECO:0000269|PubMed:28723891}.
CC -!- SIMILARITY: Belongs to the TMEM175 family. {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; CP003600; AFY94374.1; -; Genomic_DNA.
DR RefSeq; WP_015160509.1; NC_019697.1.
DR PDB; 5VRE; X-ray; 3.30 A; A/B/C/D=1-203.
DR PDBsum; 5VRE; -.
DR AlphaFoldDB; K9UJK2; -.
DR SMR; K9UJK2; -.
DR STRING; 1173020.Cha6605_3372; -.
DR TCDB; 1.A.78.2.10; the k+-selective channel in endosomes and lysosomes (kel) family.
DR EnsemblBacteria; AFY94374; AFY94374; Cha6605_3372.
DR KEGG; cmp:Cha6605_3372; -.
DR PATRIC; fig|1173020.3.peg.3871; -.
DR eggNOG; COG3548; Bacteria.
DR HOGENOM; CLU_090238_0_0_3; -.
DR OMA; PWGWAVM; -.
DR Proteomes; UP000010366; Chromosome.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0042802; F:identical protein binding; IPI:IntAct.
DR GO; GO:0005267; F:potassium channel activity; IDA:UniProtKB.
DR GO; GO:0071805; P:potassium ion transmembrane transport; IDA:UniProtKB.
DR GO; GO:0051289; P:protein homotetramerization; IDA:UniProtKB.
DR InterPro; IPR010617; TMEM175.
DR Pfam; PF06736; TMEM175; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Ion channel; Ion transport; Membrane; Potassium;
KW Potassium channel; Potassium transport; Reference proteome; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..203
FT /note="Potassium channel Cha6605_3372"
FT /id="PRO_0000442004"
FT TOPO_DOM 1..7
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305|PubMed:28723891"
FT TRANSMEM 8..31
FT /note="Helical; Name=TM1"
FT /evidence="ECO:0000269|PubMed:28723891"
FT TOPO_DOM 32..52
FT /note="Extracellular"
FT /evidence="ECO:0000305|PubMed:28723891"
FT TRANSMEM 53..78
FT /note="Helical; Name=TM2"
FT /evidence="ECO:0000269|PubMed:28723891"
FT TOPO_DOM 79..84
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305|PubMed:28723891"
FT TRANSMEM 85..110
FT /note="Helical; Name=TM3"
FT /evidence="ECO:0000269|PubMed:28723891"
FT TOPO_DOM 111..117
FT /note="Extracellular"
FT /evidence="ECO:0000305|PubMed:28723891"
FT TRANSMEM 118..142
FT /note="Helical; Name=TM4"
FT /evidence="ECO:0000269|PubMed:28723891"
FT TOPO_DOM 143..154
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305|PubMed:28723891"
FT TRANSMEM 155..181
FT /note="Helical; Name=TM5"
FT /evidence="ECO:0000269|PubMed:28723891"
FT TOPO_DOM 182..183
FT /note="Extracellular"
FT /evidence="ECO:0000305|PubMed:28723891"
FT TRANSMEM 184..199
FT /note="Helical; Name=TM6"
FT /evidence="ECO:0000269|PubMed:28723891"
FT TOPO_DOM 200..203
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305|PubMed:28723891"
FT REGION 37..42
FT /note="Short helix H1"
FT /evidence="ECO:0000269|PubMed:28723891"
FT REGION 44..50
FT /note="Short helix H2"
FT /evidence="ECO:0000269|PubMed:28723891"
FT MOTIF 12..18
FT /note="RxxxFSD motif"
FT /evidence="ECO:0000269|PubMed:28723891"
FT SITE 23
FT /note="Hydrophobic filter residue 1"
FT /evidence="ECO:0000269|PubMed:28723891"
FT SITE 27
FT /note="Hydrophobic filter residue 2"
FT /evidence="ECO:0000269|PubMed:28723891"
FT SITE 30
FT /note="Hydrophobic filter residue 3"
FT /evidence="ECO:0000269|PubMed:28723891"
FT MUTAGEN 23
FT /note="I->A,C,N: Impaired selectivity. Can conduct both
FT K(+) and Na(+)."
FT /evidence="ECO:0000269|PubMed:28723891"
FT HELIX 8..31
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 37..43
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 45..51
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 53..79
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 85..100
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 102..111
FT /evidence="ECO:0007829|PDB:5VRE"
FT STRAND 112..114
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 117..143
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 155..181
FT /evidence="ECO:0007829|PDB:5VRE"
FT HELIX 183..201
FT /evidence="ECO:0007829|PDB:5VRE"
SQ SEQUENCE 203 AA; 22674 MW; 53D7E93F759FEBE4 CRC64;
MVEAPEQSET GRIEAFSDGV FAIAITLLVL EIKVPQHKIV ETVGLVSSLL SLWPSYLAFL
TSFASILVMW VNHHRIFSLV ARTDHAFFYW NGLLLMLVTF VPFPTALLAE YLIHPQARVA
ASVYAGIFLA IAIVFNRLWK HAATADRLLA QKADRHEVDA ITKQYRFGPG LYLVAFALSF
ISVWLSVGVC FVLAIYFALR SNA
