P0AFJ7 · PITA_ECOLI

  • Protein
    Low-affinity inorganic phosphate transporter PitA
  • Gene
    pitA
  • Status
    UniProtKB reviewed (Swiss-Prot)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    5/5

Function

function

Low-affinity inorganic phosphate transporter (PubMed:11489853, PubMed:328484, PubMed:6998957, PubMed:8110778).
Mediates proton-driven uptake of soluble neutral metal phosphate (MeHP04) complexes (PubMed:8110778).
It can use Mg2+, Ca2+, Co2+ and Mn2+ (PubMed:8110778).
Activity impacts bacterial growth in low Mg2+ conditions (PubMed:30276893).
Is also involved in Zn2+ uptake, probably via formation of a ZnHPO4 complex (PubMed:10713426).
Can also transport arsenate (PubMed:328484). Involved in the uptake of tellurite (PubMed:23189244).

Miscellaneous

The Pit system in E.coli K12 consists of two transporters, PitA and PitB, which can transport phosphate independently of each other. Both proteins may have contributed to the kinetic values and substrate specificities determined in earlier studies.

Catalytic activity

Activity regulation

Phosphate uptake is dependent on the presence of divalent cations, which form soluble metal phosphate (MeHP04) complexes (PubMed:10713426, PubMed:8110778).
In Mg2+-limiting conditions, the PhoQP-regulated small protein MgtS and sRNA MgrR both regulate the PitA transporter, leading to increased intracellular Mg2+ (PubMed:30276893).
Metal phosphate uptake is inhibited at low internal pH (PubMed:8110778).
Inhibited by the uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) (PubMed:328484). Is also inhibited by the energy uncoupler 2,4-dinitrophenol and the sulfhydryl reagent N-ethylmaleimide (PubMed:6998957).

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
1.9 μMphosphate
Vmax pH TEMPERATURE[C] NOTES EVIDENCE
58 nmol/min/mg6.61.8 mM Mg2+
39 nmol/min/mg7.010.0 mM Mg2+

GO annotations

AspectTerm
Cellular Componentplasma membrane
Molecular Functionarsenate ion transmembrane transporter activity
Molecular Functionphosphate transmembrane transporter activity
Molecular Functionsolute:proton symporter activity
Molecular Functiontellurite transmembrane transporter activity
Molecular Functionzinc ion transmembrane transporter activity
Biological Processarsenate ion transmembrane transport
Biological Processmagnesium ion homeostasis
Biological Processphosphate ion transmembrane transport
Biological Processtellurite transport

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Low-affinity inorganic phosphate transporter PitA
  • Alternative names
    • Metal phosphate:H(+) symporter PitA

Gene names

    • Name
      pitA
    • Synonyms
      pit
    • Ordered locus names
      b3493, JW3460

Organism names

  • Taxonomic identifier
  • Strains
    • K12 / MG1655 / ATCC 47076
    • K12 / W3110 / ATCC 27325 / DSM 5911
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia

Accessions

  • Primary accession
    P0AFJ7
  • Secondary accessions
    • P37308
    • Q2M7F5

Proteomes

Subcellular Location

Cell inner membrane
; Multi-pass membrane protein

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain1-4Periplasmic
Transmembrane5-25Helical
Topological domain26-51Cytoplasmic
Transmembrane52-72Helical
Topological domain73-93Periplasmic
Transmembrane94-114Helical
Topological domain115-123Cytoplasmic
Transmembrane124-144Helical
Topological domain145-154Periplasmic
Transmembrane155-175Helical
Topological domain176-206Cytoplasmic
Transmembrane207-227Helical
Topological domain228-232Periplasmic
Transmembrane233-253Helical
Topological domain254-381Cytoplasmic
Transmembrane382-402Helical
Topological domain403-429Periplasmic
Transmembrane430-450Helical
Topological domain451-472Cytoplasmic
Transmembrane473-493Helical
Topological domain494-499Periplasmic

Keywords

Phenotypes & Variants

Disruption phenotype

Disruption of the gene confers increased resistance to Zn2+, associated with reduced accumulation of Zn2+ when cells are exposed to concentrations of ZnSO4 below the minimal inhibitory concentration (MIC) (PubMed:10713426).
Mutant is approximately four-fold more tolerant to tellurite, and cell viability remains almost unchanged during prolonged exposure to the toxicant as compared with wild type (PubMed:23189244).

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis220Loss of activity. Cannot grow on inorganic phosphate medium.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000807821-499Low-affinity inorganic phosphate transporter PitA

Proteomic databases

Expression

Induction

Expression is not constitutive, as initially thought, but regulated in response to levels of zinc and phosphate in the medium (PubMed:19054109).
Expression is repressed by the PhoQP-regulated MgrR sRNA (PubMed:30276893).

Interaction

Subunit

Interacts with the small protein MgtS, and this interaction contributes to an increase in intracellular Mg2+ content.

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    499
  • Mass (Da)
    53,389
  • Last updated
    2005-12-20 v1
  • Checksum
    93D551131C524084
MLHLFAGLDLHTGLLLLLALAFVLFYEAINGFHDTANAVATVIYTRAMRSQLAVVMAAVFNFLGVLLGGLSVAYAIVHMLPTDLLLNMGSSHGLAMVFSMLLAAIIWNLGTWYFGLPASSSHTLIGAIIGIGLTNALMTGTSVVDALNIPKVLSIFGSLIVSPIVGLVFAGGLIFLLRRYWSGTKKRARIHLTPAEREKKDGKKKPPFWTRIALILSAIGVAFSHGANDGQKGIGLVMLVLIGVAPAGFVVNMNATGYEITRTRDAINNVEAYFEQHPALLKQATGADQLVPAPEAGATQPAEFHCHPSNTINALNRLKGMLTTDVESYDKLSLDQRSQMRRIMLCVSDTIDKVVKMPGVSADDQRLLKKLKSDMLSTIEYAPVWIIMAVALALGIGTMIGWRRVATTIGEKIGKKGMTYAQGMSAQMTAAVSIGLASYTGMPVSTTHVLSSSVAGTMVVDGGGLQRKTVTSILMAWVFTLPAAVLLSGGLYWLSLQFL

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
U00039
EMBL· GenBank· DDBJ
AAB18469.1
EMBL· GenBank· DDBJ
Genomic DNA
U00096
EMBL· GenBank· DDBJ
AAC76518.1
EMBL· GenBank· DDBJ
Genomic DNA
AP009048
EMBL· GenBank· DDBJ
BAE77801.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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