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Q93XI5 (HKT2_ORYSI) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 40. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Cation transporter HKT2

Short name=OsHKT2
Alternative name(s):
Po-OsHKT2
Gene names
Name:HKT2
OrganismOryza sativa subsp. indica (Rice)
Taxonomic identifier39946 [NCBI]
Taxonomic lineageEukaryotaViridiplantaeStreptophytaEmbryophytaTracheophytaSpermatophytaMagnoliophytaLiliopsidaPoalesPoaceaeBEP cladeEhrhartoideaeOryzeaeOryza

Protein attributes

Sequence length530 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Seems to be involved in regulation of K+/Na+ homeostasis. Seems to act as a potassium-sodium cotransporter, which mediates increased potassium uptake under external sodium accumulation and contributes to salt-tolerance in cultivar indica Pokkali. Ref.1 Ref.2

Subcellular location

Membrane; Multi-pass membrane protein Probable.

Induction

By potassium starvation in roots. Down-regulated by sodium. Ref.1

Domain

HKT transporters are proposed to contain 4 pore-forming regions enclosed by transmembrane segments with each containing a potassium channel-like selectivity filter motif. Ref.2

Sequence similarities

Belongs to the TrkH potassium transport family. HKT (TC 2.A.38.3) subfamily. [View classification]

Caution

HKT2 is found in salt-tolerant cultivar indica Pokkali. It does not exist in cultivar indica 93-11 or japonica Nipponbare.

Ontologies

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 530530Cation transporter HKT2
PRO_0000070467

Regions

Topological domain1 – 4040Cytoplasmic Potential
Transmembrane41 – 6121Helical; Name=1; Potential
Transmembrane102 – 12221Helical; Name=2; Potential
Topological domain123 – 18664Cytoplasmic Potential
Transmembrane187 – 20721Helical; Name=3; Potential
Transmembrane260 – 28021Helical; Name=4; Potential
Topological domain281 – 31737Cytoplasmic Potential
Transmembrane318 – 33821Helical; Name=5; Potential
Transmembrane372 – 39221Helical; Name=6; Potential
Topological domain393 – 42028Cytoplasmic Potential
Transmembrane421 – 44121Helical; Name=7; Potential
Transmembrane494 – 51421Helical; Name=8; Potential
Topological domain515 – 53016Cytoplasmic Potential

Experimental info

Mutagenesis881G → S: Loss of selectivity for potassium uptake. Ref.2

Sequences

Sequence LengthMass (Da)Tools
Q93XI5 [UniParc].

Last modified December 1, 2001. Version 1.
Checksum: 73087CF493AD3360

FASTA53059,152
        10         20         30         40         50         60 
MTSIYQEFIH TKCQSFRSIG RYVLHSIVLI YRFVSLHVHP FWIQLSYFLL ISILGSVLLM 

        70         80         90        100        110        120 
FLKPSSPEFK PGYIDMLFLS TSAMTVSGLS TIEMEVLSSS QIVVLTLLML VGGEVFVSFL 

       130        140        150        160        170        180 
GLMLRLKHKH NPEFSGDRVS SVPIELDTIE PTRTVMSSEE LQIEAAAPDV PSSTIKDLKR 

       190        200        210        220        230        240 
SKRLRWFLGF VVFSYFVVIH VVGFLLVLWY ISRVSSAKAP LKKKGINIAL FSFSVTVSSF 

       250        260        270        280        290        300 
ANGGLVPTNE NMAIFSKNPG LLLLFIGQIL AGNTLYPLFL RILIWFLGKV TKLKDLKLMI 

       310        320        330        340        350        360 
KNSDELQYDY LLPKLPTAFL ASTVIGLMAS LVTLFGSVDW NSSVFDGLSS YQKIINALFM 

       370        380        390        400        410        420 
AVNARHSGEN SIDCSLIAPA VLVLFIILMY LPPSTTFALS NGDEKTANKK AKRKLGLVVR 

       430        440        450        460        470        480 
NLAFSQLACN AVFVIVALIT ERSRLRNDPL NFSALNMIFE VISAYGNVGL TTGYSCSRLQ 

       490        500        510        520        530 
KLHPGSICQD KPYSLSGWWS DEGKLLLVSV MLYGRLKAFT KGTGEYWRLW 

« Hide

References

[1]"Two types of HKT transporters with different properties of Na+ and K+ transport in Oryza sativa."
Horie T., Yoshida K., Nakayama H., Yamada K., Oiki S., Shinmyo A.
Plant J. 27:129-138(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, INDUCTION.
Strain: cv. Pokkali.
Tissue: Seedling root.
[2]"Glycine residues in potassium channel-like selectivity filters determine potassium selectivity in four-loop-per-subunit HKT transporters from plants."
Maeser P., Hosoo Y., Goshima S., Horie T., Eckelman B., Yamada K., Yoshida K., Bakker E.P., Shinmyo A., Oiki S., Schroeder J.I., Uozumi N.
Proc. Natl. Acad. Sci. U.S.A. 99:6428-6433(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, DOMAIN, MUTAGENESIS OF GLY-88.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AB061313 mRNA. Translation: BAB61791.1.

3D structure databases

ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Organism-specific databases

GrameneQ93XI5.

Family and domain databases

InterProIPR003445. Cat_transpt.
[Graphical view]
PfamPF02386. TrkH. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry nameHKT2_ORYSI
AccessionPrimary (citable) accession number: Q93XI5
Entry history
Integrated into UniProtKB/Swiss-Prot: December 20, 2005
Last sequence update: December 1, 2001
Last modified: April 16, 2014
This is version 40 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programPlant Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families