A0A0H3LM39 · ZIP_BORBR

Function

function

Selective electrodiffusional channel that mediates the uptake of Zn2+. Exploits in vivo zinc concentration gradients (maintained by cellular zinc homeostasis) to passively move zinc ions into the cytoplasm. ZIPB-mediated zinc flux is dependent upon pH, but independent of the proton motive force. Is also able to import Cd2+, but is not permeable to Co2+, Cu2+, Fe2+, Mn2+ and Ni2+.

Miscellaneous

The zinc flux through ZIPB is extremely slow in comparison with typical ion channels and is nonsaturating with respect to a zinc concentration up to 2 mM.

Catalytic activity

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site89Zn2+ 5 (UniProtKB | ChEBI); M7 metal binding site
Binding site99Cd2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site144Cd2+ 3 (UniProtKB | ChEBI); M3 metal binding site
Binding site144Zn2+ 3 (UniProtKB | ChEBI); M3 metal binding site
Binding site144Zn2+ 4 (UniProtKB | ChEBI); M6 metal binding site
Binding site177Cd2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site177Zn2+ 2 (UniProtKB | ChEBI); M5 metal binding site
Binding site178Cd2+ 2 (UniProtKB | ChEBI); M2 metal binding site
Binding site181Cd2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site181Cd2+ 2 (UniProtKB | ChEBI); M2 metal binding site
Binding site181Zn2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site207Cd2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site207Zn2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site208Cd2+ 2 (UniProtKB | ChEBI); M2 metal binding site
Binding site211Cd2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site211Cd2+ 2 (UniProtKB | ChEBI); M2 metal binding site
Binding site211Zn2+ 1 (UniProtKB | ChEBI); M1 metal binding site
Binding site240Cd2+ 2 (UniProtKB | ChEBI); M2 metal binding site
Binding site275Cd2+ 3 (UniProtKB | ChEBI); M3 metal binding site
Binding site275Zn2+ 3 (UniProtKB | ChEBI); M3 metal binding site
Binding site276Zn2+ 2 (UniProtKB | ChEBI); M5 metal binding site
Binding site286Zn2+ 5 (UniProtKB | ChEBI); M7 metal binding site

GO annotations

AspectTerm
Cellular Componentplasma membrane
Molecular Functionmetal ion transmembrane transporter activity
Biological Processzinc ion transport

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Zinc transporter ZIPB
  • Alternative names
    • BbZIP

Gene names

    • Ordered locus names
      BB2405

Organism names

Accessions

  • Primary accession
    A0A0H3LM39

Proteomes

Subcellular Location

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain1-22Periplasmic
Transmembrane23-50Helical
Topological domain51-55Extracellular
Transmembrane56-81Helical
Topological domain82-83Periplasmic
Transmembrane84-119Helical
Topological domain120-121Extracellular
Transmembrane122-145Helical
Topological domain146-165Periplasmic
Transmembrane166-190Helical
Topological domain191-192Extracellular
Transmembrane193-222Helical
Topological domain223-224Periplasmic
Transmembrane225-251Helical
Topological domain252-255Extracellular
Transmembrane256-275Helical
Topological domain276-287Periplasmic
Transmembrane288-308Helical
Topological domain309Extracellular

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis106Is more tolerant to high Zn2+ or Cd2+ concentrations due to a decreased metal uptake ability.
Mutagenesis144Is more tolerant to high Zn2+ or Cd2+ concentrations due to a decreased metal uptake ability.
Mutagenesis178Loses metal binding at M2 but does not lead to significant changes in either overall structure or metal coordination at M1; when associated with A-208 and A-240.
Mutagenesis208Loses metal binding at M2 but does not lead to significant changes in either overall structure or metal coordination at M1; when associated with A-178 and A-240.
Mutagenesis240Loses metal binding at M2 but does not lead to significant changes in either overall structure or metal coordination at M1; when associated with A-178 and A-208.
Mutagenesis276Is more tolerant to high Zn2+ or Cd2+ concentrations due to a decreased metal uptake ability.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004581951-309Zinc transporter ZIPB

Interaction

Subunit

Homodimer (PubMed:20876577, PubMed:28875161).
Also exists as a monomer (PubMed:28875161).

Family & Domains

Domain

Has an additional transmembrane segment in the N-terminus compared to many other ZIP family members. This extra helix is important for activity in vivo.
The two metal binding sites M1 and M2 that are halfway through the membrane form a binuclear metal center. The multiple conserved zinc-binding sites (M1,M5, M6 and M3) appear to constitute a route of zinc release to the cytoplasm (PubMed:28875161).
M1 is the primary transport site essential for activity, whereas M2 plays an auxiliary role presumably by serving as an additional transport site and modulating the properties of the primary transport site (PubMed:31914589).
Cd2+ at M1 can readily be replaced by externally added Zn2+, whereas Cd2+ at M2 cannot (PubMed:28875161, PubMed:31914589).
ZIP proteins seem to operate via a two-domain elevator-type mechanism for zinc transport (Probable)

Sequence similarities

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    309
  • Mass (Da)
    30,988
  • Last updated
    2015-09-16 v1
  • Checksum
    9ADF2E45AA8FE5AF
MNQPSSLAADLRGAWHAQAQSHPLITLGLAASAAGVVLLLVAGIVNALTGENRVHVGYAVLGGAAGFAATALGALMALGLRAISARTQDAMLGFAAGMMLAASAFSLILPGLDAAGTIVGPGPAAAAVVALGLGLGVLLMLGLDYFTPHEHERTGHQGPEAARVNRVWLFVLTIILHNLPEGMAIGVSFATGDLRIGLPLTSAIAIQDVPEGLAVALALRAVGLPIGRAVLVAVASGLMEPLGALVGVGISSGFALAYPISMGLAAGAMIFVVSHEVIPETHRNGHETTATVGLMAGFALMMFLDTALG

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BX640444
EMBL· GenBank· DDBJ
CAE32899.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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