O87953 · KTRB_VIBAL

  • Protein
    Ktr system potassium uptake protein B
  • Gene
    ktrB
  • Status
    UniProtKB reviewed (Swiss-Prot)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    5/5

Function

function

Part of the Na+-dependent high affinity K+ uptake system KtrAB. KtrB is the K+-translocating subunit.

Miscellaneous

KtrB alone mediates slow Na+-independent K+ uptake, as well as K+-independent Na+ uptake.

Activity regulation

K+ transport is stimulated by Na+.

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
0.025 mMK+
6 mMNa+
Vmax pH TEMPERATURE[C] NOTES EVIDENCE
200 nmol/min/mgwith K+ as substrate
110 nmol/min/mgwith Na+ as substrate

GO annotations

AspectTerm
Cellular Componentplasma membrane
Molecular Functionpotassium:chloride symporter activity

Keywords

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Ktr system potassium uptake protein B
  • Short names
    K(+)-uptake protein KtrB

Gene names

    • Name
      ktrB

Organism names

  • Taxonomic identifier
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Vibrionales > Vibrionaceae > Vibrio

Accessions

  • Primary accession
    O87953

Subcellular Location

Cell inner membrane
; Multi-pass membrane protein

Features

Showing features for transmembrane, intramembrane.

TypeIDPosition(s)Description
Transmembrane27-47Helical
Intramembrane54-74
Transmembrane86-106Helical
Transmembrane141-161Helical
Intramembrane169-189
Transmembrane201-221Helical
Transmembrane240-260Helical
Intramembrane291-313
Transmembrane318-340Helical
Transmembrane362-382Helical
Intramembrane390-410
Transmembrane418-438Helical

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis70Decrease in K+ uptake activity.
Mutagenesis70Exhibits very low K+ uptake activity.
Mutagenesis185Decrease in K+ uptake activity.
Mutagenesis185Exhibits very low K+ uptake activity.
Mutagenesis290Decrease in K+ uptake activity.
Mutagenesis290Lack of K+ uptake activity.
Mutagenesis314Does not affect Vmax for K+ transport.
Mutagenesis316Increases Vmax for K+ transport.
Mutagenesis317Increases Vmax for K+ transport.
Mutagenesis318Does not affect Vmax for K+ transport.
Mutagenesis320Increases Vmax for K+ transport.
Mutagenesis321Increases Vmax for K+ transport.
Mutagenesis322Increases Vmax for K+ transport.
Mutagenesis323Increases Vmax for K+ transport.
Mutagenesis324Increases Vmax for K+ transport.
Mutagenesis325Increases Vmax for K+ transport.
Mutagenesis326Increases Vmax for K+ transport.
Mutagenesis326-328Abolishes binding to KtrA. Transports Na+ faster.
Mutagenesis327Increases Vmax for K+ transport.
Mutagenesis402Exhibits very low K+ uptake activity.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004300331-455Ktr system potassium uptake protein B

Interaction

Subunit

The uptake system is composed of KtrA and KtrB.

Protein-protein interaction databases

Family & Domains

Domain

Contains four repeated domains, each composed of two transmembrane helices connected by a putative pore loop (p-loop). Four conserved glycine residues in the p-loops are part of a selectivity filter for K+ ions.

Sequence similarities

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    455
  • Mass (Da)
    49,664
  • Last updated
    1998-11-01 v1
  • Checksum
    3E93A4F5FC73B2C2
MTQFHQRGVFYVPDGKRDKAKGGEPRIILLSFLGVLLPSAVLLTLPVFSVSGLSITDALFTATSAISVTGLGVVDTGQHFTLAGKILLMCLMQIGGLGQMTLSAVLLYMFGVRLSLRQQALAKEALGQERQVNLRRLVKKIVTFALVAEAIGFVFLSYRWVPEMGWQTGMFYALFHSISAFNNAGFALFSDSMMSFVNDPLVSFTLAGLFIFGGLGFTVIGDVWRHWRKGFHFLHIHTKIMLIATPLLLLVGTVLFWLLERHNPNTMGSLTTGGQWLAAFFQSASARTAGFNSVDLTQFTQPALLIMIVLMLIGAGSTSTGGGIKVSTFAVAFMATWTFLRQKKHVVMFKRTVNWPTVTKSLAIIVVSGAILTTAMFLLMLTEKASFDKVMFETISAFATVGLTAGLTAELSEPGKYIMIVVMIIGRIGPLTLAYMLARPEPTLIKYPEDTVLTG

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
D89592
EMBL· GenBank· DDBJ
BAA32063.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

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