O87953 · KTRB_VIBAL
- ProteinKtr system potassium uptake protein B
- GenektrB
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids455 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
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 mM | K+ | |||||
6 mM | Na+ |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
200 nmol/min/mg | with K+ as substrate | ||||
110 nmol/min/mg | with Na+ as substrate |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | plasma membrane | |
Molecular Function | potassium:chloride symporter activity |
Keywords
- Biological process
- Ligand
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameKtr system potassium uptake protein B
- Short namesK(+)-uptake protein KtrB
Gene names
Organism names
- Organism
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Vibrionales > Vibrionaceae > Vibrio
Accessions
- Primary accessionO87953
Subcellular Location
UniProt Annotation
GO Annotation
Cell inner membrane ; Multi-pass membrane protein
Features
Showing features for transmembrane, intramembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 27-47 | Helical | ||||
Sequence: IILLSFLGVLLPSAVLLTLPV | ||||||
Intramembrane | 54-74 | |||||
Sequence: SITDALFTATSAISVTGLGVV | ||||||
Transmembrane | 86-106 | Helical | ||||
Sequence: ILLMCLMQIGGLGQMTLSAVL | ||||||
Transmembrane | 141-161 | Helical | ||||
Sequence: IVTFALVAEAIGFVFLSYRWV | ||||||
Intramembrane | 169-189 | |||||
Sequence: GMFYALFHSISAFNNAGFALF | ||||||
Transmembrane | 201-221 | Helical | ||||
Sequence: LVSFTLAGLFIFGGLGFTVIG | ||||||
Transmembrane | 240-260 | Helical | ||||
Sequence: IMLIATPLLLLVGTVLFWLLE | ||||||
Intramembrane | 291-313 | |||||
Sequence: FNSVDLTQFTQPALLIMIVLMLI | ||||||
Transmembrane | 318-340 | Helical | ||||
Sequence: TSTGGGIKVSTFAVAFMATWTFL | ||||||
Transmembrane | 362-382 | Helical | ||||
Sequence: LAIIVVSGAILTTAMFLLMLT | ||||||
Intramembrane | 390-410 | |||||
Sequence: VMFETISAFATVGLTAGLTAE | ||||||
Transmembrane | 418-438 | Helical | ||||
Sequence: IMIVVMIIGRIGPLTLAYMLA |
Keywords
- Cellular component
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 70 | Decrease in K+ uptake activity. | ||||
Sequence: G → A or S | ||||||
Mutagenesis | 70 | Exhibits very low K+ uptake activity. | ||||
Sequence: G → D | ||||||
Mutagenesis | 185 | Decrease in K+ uptake activity. | ||||
Sequence: G → A or D | ||||||
Mutagenesis | 185 | Exhibits very low K+ uptake activity. | ||||
Sequence: G → S | ||||||
Mutagenesis | 290 | Decrease in K+ uptake activity. | ||||
Sequence: G → A | ||||||
Mutagenesis | 290 | Lack of K+ uptake activity. | ||||
Sequence: G → D or S | ||||||
Mutagenesis | 314 | Does not affect Vmax for K+ transport. | ||||
Sequence: G → A | ||||||
Mutagenesis | 316 | Increases Vmax for K+ transport. | ||||
Sequence: G → A or S | ||||||
Mutagenesis | 317 | Increases Vmax for K+ transport. | ||||
Sequence: S → C | ||||||
Mutagenesis | 318 | Does not affect Vmax for K+ transport. | ||||
Sequence: T → C | ||||||
Mutagenesis | 320 | Increases Vmax for K+ transport. | ||||
Sequence: T → C | ||||||
Mutagenesis | 321 | Increases Vmax for K+ transport. | ||||
Sequence: G → A or S | ||||||
Mutagenesis | 322 | Increases Vmax for K+ transport. | ||||
Sequence: G → C | ||||||
Mutagenesis | 323 | Increases Vmax for K+ transport. | ||||
Sequence: G → S | ||||||
Mutagenesis | 324 | Increases Vmax for K+ transport. | ||||
Sequence: I → C | ||||||
Mutagenesis | 325 | Increases Vmax for K+ transport. | ||||
Sequence: K → C, D, H, Q, or R | ||||||
Mutagenesis | 326 | Increases Vmax for K+ transport. | ||||
Sequence: V → C, S, or T | ||||||
Mutagenesis | 326-328 | Abolishes binding to KtrA. Transports Na+ faster. | ||||
Sequence: Missing | ||||||
Mutagenesis | 327 | Increases Vmax for K+ transport. | ||||
Sequence: S → C | ||||||
Mutagenesis | 402 | Exhibits very low K+ uptake activity. | ||||
Sequence: G → A, D, or S |
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000430033 | 1-455 | Ktr system potassium uptake protein B | |||
Sequence: MTQFHQRGVFYVPDGKRDKAKGGEPRIILLSFLGVLLPSAVLLTLPVFSVSGLSITDALFTATSAISVTGLGVVDTGQHFTLAGKILLMCLMQIGGLGQMTLSAVLLYMFGVRLSLRQQALAKEALGQERQVNLRRLVKKIVTFALVAEAIGFVFLSYRWVPEMGWQTGMFYALFHSISAFNNAGFALFSDSMMSFVNDPLVSFTLAGLFIFGGLGFTVIGDVWRHWRKGFHFLHIHTKIMLIATPLLLLVGTVLFWLLERHNPNTMGSLTTGGQWLAAFFQSASARTAGFNSVDLTQFTQPALLIMIVLMLIGAGSTSTGGGIKVSTFAVAFMATWTFLRQKKHVVMFKRTVNWPTVTKSLAIIVVSGAILTTAMFLLMLTEKASFDKVMFETISAFATVGLTAGLTAELSEPGKYIMIVVMIIGRIGPLTLAYMLARPEPTLIKYPEDTVLTG |
Interaction
Structure
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
Belongs to the TrkH potassium transport family. Ktr (TC 2.A.38.4) subfamily.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length455
- Mass (Da)49,664
- Last updated1998-11-01 v1
- Checksum3E93A4F5FC73B2C2
Keywords
- Technical term