Structural highlights
4j90 is a 2 chain structure with sequence from Bacillus subtilis subsp. subtilis str. 168. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | |
| Related: | 2hms, 2hmt, 2hmu, 2hmv, 2hmw, 4j91 |
| Gene: | ktrA, yuaA, BSU31090 (Bacillus subtilis subsp. subtilis str. 168) |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Function
[KTRA_BACSU] Catalytic subunit of the KtrAB potassium uptake transporter. The 2 major potassium transporter complexes KtrAB and KtrCD confer resistance to both suddenly imposed and prolonged osmotic stress.[1]
Publication Abstract from PubMed
In bacteria, archaea, fungi and plants the Trk, Ktr and HKT ion transporters are key components of osmotic regulation, pH homeostasis and resistance to drought and high salinity. These ion transporters are functionally diverse: they can function as Na(+) or K(+) channels and possibly as cation/K(+) symporters. They are closely related to potassium channels both at the level of the membrane protein and at the level of the cytosolic regulatory domains. Here we describe the crystal structure of a Ktr K(+) transporter, the KtrAB complex from Bacillus subtilis. The structure shows the dimeric membrane protein KtrB assembled with a cytosolic octameric KtrA ring bound to ATP, an activating ligand. A comparison between the structure of KtrAB-ATP and the structures of the isolated full-length KtrA protein with ATP or ADP reveals a ligand-dependent conformational change in the octameric ring, raising new ideas about the mechanism of activation in these transporters.
The structure of the KtrAB potassium transporter.,Vieira-Pires RS, Szollosi A, Morais-Cabral JH Nature. 2013 Apr 18;496(7445):323-8. doi: 10.1038/nature12055. PMID:23598340[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Holtmann G, Bakker EP, Uozumi N, Bremer E. KtrAB and KtrCD: two K+ uptake systems in Bacillus subtilis and their role in adaptation to hypertonicity. J Bacteriol. 2003 Feb;185(4):1289-98. PMID:12562800
- ↑ Vieira-Pires RS, Szollosi A, Morais-Cabral JH. The structure of the KtrAB potassium transporter. Nature. 2013 Apr 18;496(7445):323-8. doi: 10.1038/nature12055. PMID:23598340 doi:10.1038/nature12055
