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HAMAP rule MF_01128

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General rule information [?]

Accession MF_01128
Dates 22-APR-2003 (Created)
19-NOV-2022 (Last updated, Version 37)
Name CLC_ClcA
Scope(s) Bacteria
Template(s) P37019 (CLCA_ECOLI); [ Recover all ]
Triggered by HAMAP; MF_01128 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier CLCA
Protein name RecName: Full=H(+)/Cl(-) exchange transporter ClcA;
case <OC:Enterobacterales>
Gene name Name=clcA; Synonyms=eriC;
Gene name Name=clcA;
end case

Comments [?]

FUNCTIONProton-coupled chloride transporter. Functions as antiport system and exchanges two chloride ions for 1 proton. Probably acts as an electrical shunt for an outwardly-directed proton pump that is linked to amino acid decarboxylation, as part of the extreme acid resistance (XAR) response.
CATALYTIC ACTIVITY Reaction=2 chloride(in) + H(+)(out) = 2 chloride(out) + H(+)(in); Xref=Rhea:RHEA:29567, ChEBI:CHEBI:15378, ChEBI:CHEBI:17996;
case not defined <Property:Membrane> or <Property:Membrane=1>
SUBCELLULAR LOCATIONCell membrane; Multi-pass membrane protein.
else case <Property:Membrane=2>
SUBCELLULAR LOCATIONCell inner membrane; Multi-pass membrane protein.
end case
SIMILARITYBelongs to the chloride channel (TC 2.A.49) family. ClcA subfamily.

Keywords [?]

case defined <Property:Membrane> and <Property:Membrane=2>
Cell inner membrane
end case
Cell membrane
Ion transport
Transmembrane helix

Gene Ontology [?]

GO:0015297; Molecular function:antiporter activity
GO:0006821; Biological process:chloride transport
GO:0005886; Cellular component:plasma membrane

Cross-references [?]

Pfam PF00654; Voltage_CLC; 1;
General Transmembrane; -; 11;

Features [?]

From: CLCA_ECOLI (P37019)
Key From To Description Tag Condition FTGroup
case defined <Property:Membrane> and <Property:Membrane=2>
TOPO_DOM Nter 32 /note="Cytoplasmic"
TRANSMEM 33 69 /note="Helical"
TOPO_DOM 70 76 /note="Periplasmic"
TRANSMEM 77 100 /note="Helical"
INTRAMEM 109 116 /note="Helical"
TOPO_DOM 117 123 /note="Cytoplasmic"
TRANSMEM 124 141 /note="Helical"
TRANSMEM 148 166 /note="Helical"
TOPO_DOM 167 176 /note="Cytoplasmic"
INTRAMEM 177 189 /note="Helical"
INTRAMEM 193 201 /note="Helical"
TOPO_DOM 202 214 /note="Cytoplasmic"
TRANSMEM 215 232 /note="Helical"
TOPO_DOM 233 252 /note="Periplasmic"
TRANSMEM 253 281 /note="Helical"
TOPO_DOM 282 287 /note="Cytoplasmic"
TRANSMEM 288 309 /note="Helical"
TOPO_DOM 310 329 /note="Periplasmic"
TRANSMEM 330 349 /note="Helical"
TRANSMEM 355 376 /note="Helical"
TOPO_DOM 377 386 /note="Periplasmic"
INTRAMEM 387 401 /note="Helical"
INTRAMEM 402 404 /note="Note=Loop between two helices"
INTRAMEM 405 416 /note="Helical"
INTRAMEM 417 421 /note="Note=Loop between two helices"
TRANSMEM 422 438 /note="Helical"
TOPO_DOM 439 Cter /note="Cytoplasmic"
MOTIF 106 110 /note="Selectivity filter part_1"
MOTIF 146 150 /note="Selectivity filter part_2"
MOTIF 355 359 /note="Selectivity filter part_3"
end case
BINDING 107 107 /ligand="chloride"
BINDING 356 356 /ligand="chloride"
BINDING 357 357 /ligand="chloride"
BINDING 445 445 /ligand="chloride"
SITE 148 148 /note="Mediates proton transfer from the outer aqueous phase to the interior of the protein; involved in linking H(+) and Cl(-) transport" E
SITE 203 203 /note="Mediates proton transfer from the protein to the inner aqueous phase" E

Additional information [?]

Size range 467-478 amino acids
Related rules None
Fusion Nter: None Cter: None
Comments ClcA from E.coli was originally characterized as a voltage-gated chloride channel. It has now become clear that it is, in fact, a transporter. E.coli has at least one paralog, ClcB, and maybe YfeO, for which there is no electrophysiological characterization - they may or may not be transporters too. This family of proteins with high similarity to ClcA have, therefore, been considered as transporters as well. Further characterization is needed to distinguish ion channels from transporters, as it seems that the structural boundary separating channels and transporters is not as clear-cut as generally thought.

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