KtrB

• Description: high affinity potassium transporter KtrA-KtrB, integral membrane subunit
  
  

Gene name	ktrB
Synonyms	yubG
Essential	no
Product	high affinity potassium transporter KtrA-KtrB, integral membrane subunit (proton symport)
Function	potassium uptake
Gene expression levels in SubtiExpress: ktrB
Interactions involving this protein in SubtInteract: KtrB
Metabolic function and regulation of this protein in SubtiPathways: Metal ion homeostasis, Stress
MW, pI	48 kDa, 10.116
Gene length, protein length	1335 bp, 445 aa
Immediate neighbours	ktrA, yubF
Sequences	Protein DNA DNA_with_flanks
Genetic context This image was kindly provided by SubtiList
Expression at a glance   PubMed

Categories containing this gene/protein

transporters/ other, metal ion homeostasis (K, Na, Ca, Mg), coping with hyper-osmotic stress, membrane proteins

This gene is a member of the following regulons

YdaO riboswitch

The gene

Basic information

• Locus tag: BSU31100

Database entries

• DBTBS entry: no entry

• SubtiList entry: [1]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity:

• Protein family:

• Paralogous protein(s): KtrD

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions:
  • KtrB forms dimers PubMed
  • KtrA-KtrB PubMed, composed of an octameric KtrA ring and two KtrB dimers PubMed

• Localization: integral membrane protein PubMed

Database entries

• Structure:
  • 4J7C (the KtrA-KtrB complex) PubMed

• UniProt: O32081

• KEGG entry: [2]

• E.C. number:

Expression and regulation

• Operon: ktrA-ktrB PubMed

• Expression browser: ktrB PubMed

• Sigma factor:

• Regulation:
  • induced if the energy charge is low (ydaO riboswitch) PubMed

• Regulatory mechanism:
  • expression is controlled via termination antitermination by the ydaO riboswitch PubMed

• Additional information:

Biological materials

• Mutant:
  • 1A954 ( ktrB::kan), PubMed, available at BGSC
  • GHB1 (D(ktrA-ktrB)::aphA3), available in Erhard Bremer's lab
  • GP92 (D(ktrA-ktrB)::aphA3), available in Jörg Stülke's lab

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

Labs working on this gene/protein

Erhard Bremer, University of Marburg, Germany homepage

References

Ricardo S Vieira-Pires, Andras Szollosi, João H Morais-Cabral
The structure of the KtrAB potassium transporter.
Nature: 2013, 496(7445);323-8
[PubMed:23598340] [WorldCat.org] [DOI] (I p)

Peter Y Watson, Martha J Fedor
The ydaO motif is an ATP-sensing riboswitch in Bacillus subtilis.
Nat Chem Biol: 2012, 8(12);963-5
[PubMed:23086297] [WorldCat.org] [DOI] (I p)

Kirsten F Block, Ming C Hammond, Ronald R Breaker
Evidence for widespread gene control function by the ydaO riboswitch candidate.
J Bacteriol: 2010, 192(15);3983-9
[PubMed:20511502] [WorldCat.org] [DOI] (I p)

Ronald A Albright, Kyu Joh, João H Morais-Cabral
Probing the structure of the dimeric KtrB membrane protein.
J Biol Chem: 2007, 282(48);35046-55
[PubMed:17932047] [WorldCat.org] [DOI] (P p)

Ronald A Albright, José-Luís Vazquez Ibar, Chae Un Kim, Sol M Gruner, João Henrique Morais-Cabral
The RCK domain of the KtrAB K+ transporter: multiple conformations of an octameric ring.
Cell: 2006, 126(6);1147-59
[PubMed:16990138] [WorldCat.org] [DOI] (P p)

Gudrun Holtmann, Evert P Bakker, Nobuyuki Uozumi, Erhard Bremer
KtrAB and KtrCD: two K+ uptake systems in Bacillus subtilis and their role in adaptation to hypertonicity.
J Bacteriol: 2003, 185(4);1289-98
[PubMed:12562800] [WorldCat.org] [DOI] (P p)