4J90

Square-shaped octameric structure of KtrA with ATP bound

Summary for 4J90

• Entry DOI: 10.2210/pdb4j90/pdb
• Related: 2HMS 2HMT 2HMU 2HMV 2HMW 4J91
• Descriptor: Ktr system potassium uptake protein A, ADENOSINE-5'-TRIPHOSPHATE (3 entities in total)
• Functional Keywords: square-shaped octameric ring, rck domain, potassium transport regulation, ktrb membrane protein, cytosol, metal transport
• Biological source: Bacillus subtilis
• Cellular location: Cell membrane; Peripheral membrane protein; Cytoplasmic side (By similarity): O32080
• Total number of polymer chains: 2
• Total formula weight: 50847.88

Authors

Vieira-Pires, R.S.,Morais-Cabral, J.H. (deposition date: 2013-02-15, release date: 2013-04-17, Last modification date: 2024-03-20)

Primary citation

Vieira-Pires, R.S.,Szollosi, A.,Morais-Cabral, J.H.
The structure of the KtrAB potassium transporter
Nature, 496:323-328, 2013

PubMed Abstract: 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.

PubMed: 23598340
DOI: 10.1038/nature12055

Experimental method

X-RAY DIFFRACTION (3.24 Å)