Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
twitter

Escherichia coli K-12 substr. MG1655 Transporter: K+ : H+ antiporter KefC



Gene: kefC Accession Numbers: EG10521 (EcoCyc), b0047, ECK0048

Synonyms: trkC, KefC potassium CPA2 transporter

Regulation Summary Diagram: ?

Subunit composition of K+ : H+ antiporter KefC = [KefC]2

Summary:
KefB and KefC are two independent glutathione-regulated potassium efflux systems, which play a role in protecting the cell from electrophile toxicity. Mutations in kefB and kefC affect potassium efflux at neutral pH, can be complemented by the cloned genes and probably function via potassium/proton antiport [Booth85, Bakker87]. Potassium efflux by KefB or KefC is activated by adducts formed by reaction of glutathione with electrophilic compounds such as N-ethylmaleimide, methylglyoxal and chlorodinitrobenzene [Ferguson93, Elmore90]. Potassium efflux mediated by KefB and KefC leads to acidification of the cytoplasm, which protects the cell from electrophile toxicity [Ferguson97a, Ferguson95]. KefB and KefC differ in their activation by methylglyoxal, with KefC only weakly activated [Ness99]. KefC is a member of the CPA2 family of monovalent cation/proton antiporters. The ancillary protein, KefF, is required for maximum activity of KefC [Miller00a]. In addition to KefB and KefC, additional unidentified potassium efflux systems exist.

KefC consists of a membrane domain attached to a C-terminal KTN (K+ transport, nucleotide binding) domain via a flexible linker. Mutational analyses suggest the presence of a single binding site for GSH or its adducts at the interface between dimeric KTN domains. The crystal structure of the C terminal domain of KefC in association with KefF has been resolved at 2.4Å resolution [Roosild09]. Crystal structures of the C-terminal domain of KefC in complex with KefF and either the inhibitory ligand GSH or the activating adduct ESG (N-ethylsuccinimido-S-glutathione) have also been solved. Significant conformational change in the KTN domain is associated with binding of the activating adduct but the mechanism by which local conformational change in this region might influence the associated transmembrane pore remains unclear [Roosild10].

Locations: inner membrane

Map Position: [47,769 -> 49,631] (1.03 centisomes)
Length: 1863 bp / 620 aa

Molecular Weight of Polypeptide: 67.796 kD (from nucleotide sequence)

Molecular Weight of Multimer: 270.0 kD (experimental) [Roosild09]

Unification Links: ASAP:ABE-0000161 , CGSC:82 , DIP:DIP-10072N , EchoBASE:EB0516 , EcoGene:EG10521 , EcoliWiki:b0047 , Mint:MINT-1257196 , ModBase:P03819 , OU-Microarray:b0047 , PDB:3L9W , PDB:3L9X , PortEco:kefC , PR:PRO_000023062 , Pride:P03819 , Protein Model Portal:P03819 , RefSeq:NP_414589 , RegulonDB:EG10521 , SMR:P03819 , String:511145.b0047 , UniProt:P03819

Relationship Links: InterPro:IN-FAMILY:IPR003148 , InterPro:IN-FAMILY:IPR004771 , InterPro:IN-FAMILY:IPR006036 , InterPro:IN-FAMILY:IPR006153 , InterPro:IN-FAMILY:IPR016040 , InterPro:IN-FAMILY:IPR023941 , PDB:Structure:3EYW , PDB:Structure:3L9W , PDB:Structure:3L9X , Pfam:IN-FAMILY:PF00999 , Pfam:IN-FAMILY:PF02254 , Prints:IN-FAMILY:PR00335 , Prosite:IN-FAMILY:PS51201

In Paralogous Gene Group: 515 (2 members) , 552 (2 members)

Gene-Reaction Schematic: ?

GO Terms:

Biological Process: GO:0006813 - potassium ion transport Inferred from experiment Inferred by computational analysis [UniProtGOA11a, GOA01, Ferguson00, Ferguson95, Bakker87]
GO:0006885 - regulation of pH Inferred from experiment [Ferguson00]
GO:0009636 - response to toxic substance Inferred from experiment [Elmore90]
GO:0051595 - response to methylglyoxal Inferred from experiment Inferred by computational analysis [GOA01, Ferguson95]
GO:0071805 - potassium ion transmembrane transport Inferred by computational analysis Inferred from experiment [Elmore90, GOA06, GOA01]
GO:0006810 - transport Inferred by computational analysis [UniProtGOA11a]
GO:0006811 - ion transport Inferred by computational analysis [UniProtGOA11a]
GO:0006812 - cation transport Inferred by computational analysis [GOA01]
GO:0098655 - cation transmembrane transport Inferred by computational analysis [GOA01]
GO:1902600 - hydrogen ion transmembrane transport Inferred by computational analysis [GOA01]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Roosild09]
GO:0015503 - glutathione-regulated potassium exporter activity Inferred from experiment Inferred by computational analysis [GOA06, GOA01, Elmore90]
GO:0015643 - toxic substance binding Inferred from experiment Inferred by computational analysis [GOA01, Roosild10]
GO:0019899 - enzyme binding Inferred from experiment Inferred by computational analysis [GOA01, Miller00a]
GO:0042803 - protein homodimerization activity Inferred from experiment [Roosild09]
GO:0000166 - nucleotide binding Inferred by computational analysis [UniProtGOA11a]
GO:0008324 - cation transmembrane transporter activity Inferred by computational analysis [GOA01]
GO:0015079 - potassium ion transmembrane transporter activity Inferred by computational analysis [GOA01]
GO:0015297 - antiporter activity Inferred by computational analysis [UniProtGOA11a]
GO:0015299 - solute:proton antiporter activity Inferred by computational analysis [GOA01]
Cellular Component: GO:0005886 - plasma membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA01, DiazMejia09, Daley05]
GO:0005887 - integral component of plasma membrane Inferred from experiment Inferred by computational analysis [GOA06, GOA01, Munro91, Roosild09]
GO:0016020 - membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11a, Douglas]
GO:0016021 - integral component of membrane Inferred by computational analysis [UniProtGOA11a, GOA01]

MultiFun Terms: cell processes protection detoxification
cell structure membrane
transport Electrochemical potential driven transporters Porters (Uni-, Sym- and Antiporters)

Essentiality data for kefC knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB enriched Yes 37 Aerobic 6.95   Yes [Gerdes03, Comment 1]
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 2]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 3]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 2]
Yes [Feist07, Comment 4]

Credits:
Created 25-Aug-2009 by Mackie A , Macquarie University
Last-Curated ? 12-Dec-2010 by Mackie A , Macquarie University


Enzymatic reaction of: K+ : H+ antiporter KefC


Sequence Features

Feature Class Location Common Name Attached Group Citations Comment
Transmembrane-Region 4 -> 24    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 26 -> 46    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 54 -> 74    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 90 -> 110    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 114 -> 134    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 149 -> 169    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 178 -> 198    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 214 -> 233    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 237 -> 254    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Protein-Segment 259 -> 267    
[UniProt13]
UniProt: Important for the regulation of potassium conductance; Sequence Annotation Type: region of interest.
Mutagenesis-Variant 262    
[UniProt13]
Alternate sequence: E → K; UniProt: Increases potassium efflux in the absence of glutathione, but not in the presence of glutathione. Increases constitutive potassium efflux; when associated with D-551.
Mutagenesis-Variant 264    
[Roosild09, UniProt13]
Alternate sequence: D → A; UniProt: Increases constitutive potassium efflux.
Transmembrane-Region 270 -> 290    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 294 -> 314    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 327 -> 347    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 359 -> 379    
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Conserved-Region 401 -> 523    
[UniProt10b]
UniProt: RCK N-terminal;
Protein-Binding-Region 401 -> 523 KTN domain  
[Roosild09]
K+ transport, nucleotide binding
Nucleotide-Phosphate-Binding-Region 408 -> 410   AMP
[UniProt14]
UniProt: AMP.
Mutagenesis-Variant 412    
[Roosild10, UniProt13]
Alternate sequence: Q → K; UniProt: Increases constitutive potassium efflux and abolishes regulation of potassium efflux by glutathione and glutathione adducts.
Alternate sequence: Q → A; UniProt: Increases constitutive potassium efflux and reduces glutathione-mediated inhibition of potassium efflux.
Amino-Acid-Sites-That-Bind 412    
[UniProt13]
UniProt: Glutathione; shared with dimeric partner.
Mutagenesis-Variant 416    
[Roosild10, Roosild09, UniProt13]
Alternate sequence: R → S; UniProt: Increased constitutive potassium efflux.
Alternate sequence: R → A; UniProt: Increases constitutive potassium efflux and abolishes regulation of potassium efflux by glutathione and glutathione adducts; when associated with A-516 and A-551.
Nucleotide-Phosphate-Binding-Region 429 -> 430   AMP
[UniProt14]
UniProt: AMP.
Amino-Acid-Sites-That-Bind 434    
[UniProt13]
UniProt: AMP.
Mutagenesis-Variant 441    
[Roosild10, UniProt13]
Alternate sequence: F → Y; UniProt: No effect on activation of potassium efflux by glutathione adducts.
Alternate sequence: F → W; UniProt: No effect on activation of potassium efflux by glutathione adducts.
Alternate sequence: F → L; UniProt: Reduced activation of potassium efflux by glutathione adducts.
Alternate sequence: F → D; UniProt: Reduced activation of potassium efflux by glutathione adducts.
Nucleotide-Phosphate-Binding-Region 449 -> 450   AMP
[UniProt14]
UniProt: AMP.
Amino-Acid-Sites-That-Bind 472    
[UniProt13]
UniProt: AMP.
Amino-Acid-Sites-That-Bind 496    
[UniProt13]
UniProt: AMP.
Protein-Segment 498 -> 500    
[UniProt13]
UniProt: Glutathione binding; Sequence Annotation Type: region of interest.
Mutagenesis-Variant 499    
[Roosild10, UniProt13]
Alternate sequence: D → S; UniProt: No effect on potassium efflux.
Alternate sequence: D → G; UniProt: Mildly reduced activation of potassium efflux by glutathione adducts.
Alternate sequence: D → A; UniProt: Strongly reduced activation of potassium efflux by glutathione adducts.
Mutagenesis-Variant 516    
[Roosild10, UniProt13]
Alternate sequence: R → A; UniProt: Increases constitutive potassium efflux and abolishes regulation of potassium efflux by glutathione and glutathione adducts; when associated with A-416 and A-551.
Amino-Acid-Sites-That-Bind 516    
[UniProt13]
UniProt: Glutathione.
Mutagenesis-Variant 520    
[Roosild09, UniProt13]
Alternate sequence: E → G; UniProt: Strongly reduced potassium efflux.
Mutagenesis-Variant 522    
[Roosild09, UniProt13]
Alternate sequence: A → V; UniProt: Strongly reduced potassium efflux.
Mutagenesis-Variant 526    
[Roosild09, UniProt13]
Alternate sequence: G → V; UniProt: Strongly reduced potassium efflux.
Mutagenesis-Variant 551    
[Roosild10, Roosild09, UniProt13]
Alternate sequence: N → D; UniProt: Increases constitutive potassium efflux; when associated with K-262.
Alternate sequence: N → A; UniProt: Increases constitutive potassium efflux and abolishes regulation of potassium efflux by glutathione and glutathione adducts; when associated with A-416 and A-516.


Gene Local Context (not to scale): ?

Transcription Unit:

Notes:

History:
10/20/97 Gene b0047 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10521; confirmed by SwissProt match.


References

Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

Bakker87: Bakker EP, Booth IR, Dinnbier U, Epstein W, Gajewska A (1987). "Evidence for multiple K+ export systems in Escherichia coli." J Bacteriol 1987;169(8);3743-9. PMID: 3301813

Booth85: Booth IR, Epstein W, Giffard PM, Rowland GC (1985). "Roles of the trkB and trkC gene products of Escherichia coli in K+ transport." Biochimie 1985;67(1);83-9. PMID: 3888294

Daley05: Daley DO, Rapp M, Granseth E, Melen K, Drew D, von Heijne G (2005). "Global topology analysis of the Escherichia coli inner membrane proteome." Science 308(5726);1321-3. PMID: 15919996

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Douglas: Douglas RM, Ritchie GY, Munro AW, McLaggan D, Booth IR "The K(+)-efflux system, KefC, in Escherichia coli: genetic evidence for oligomeric structure." Mol Membr Biol 11(1);55-61. PMID: 8019602

Elmore90: Elmore MJ, Lamb AJ, Ritchie GY, Douglas RM, Munro A, Gajewska A, Booth IR (1990). "Activation of potassium efflux from Escherichia coli by glutathione metabolites." Mol Microbiol 1990;4(3);405-12. PMID: 2192231

Feist07: Feist AM, Henry CS, Reed JL, Krummenacker M, Joyce AR, Karp PD, Broadbelt LJ, Hatzimanikatis V, Palsson BO (2007). "A genome-scale metabolic reconstruction for Escherichia coli K-12 MG1655 that accounts for 1260 ORFs and thermodynamic information." Mol Syst Biol 3;121. PMID: 17593909

Ferguson00: Ferguson GP, Battista JR, Lee AT, Booth IR (2000). "Protection of the DNA during the exposure of Escherichia coli cells to a toxic metabolite: the role of the KefB and KefC potassium channels." Mol Microbiol 35(1);113-22. PMID: 10632882

Ferguson93: Ferguson GP, Munro AW, Douglas RM, McLaggan D, Booth IR (1993). "Activation of potassium channels during metabolite detoxification in Escherichia coli." Mol Microbiol 1993;9(6);1297-303. PMID: 7934942

Ferguson95: Ferguson GP, McLaggan D, Booth IR (1995). "Potassium channel activation by glutathione-S-conjugates in Escherichia coli: protection against methylglyoxal is mediated by cytoplasmic acidification." Mol Microbiol 1995;17(6);1025-33. PMID: 8594323

Ferguson97a: Ferguson GP, Nikolaev Y, McLaggan D, Maclean M, Booth IR (1997). "Survival during exposure to the electrophilic reagent N-ethylmaleimide in Escherichia coli: role of KefB and KefC potassium channels." J Bacteriol 1997;179(4);1007-12. PMID: 9023177

Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938

GOA01: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394

Miller00a: Miller S, Ness LS, Wood CM, Fox BC, Booth IR (2000). "Identification of an ancillary protein, YabF, required for activity of the KefC glutathione-gated potassium efflux system in Escherichia coli." J Bacteriol 182(22);6536-40. PMID: 11053405

Munro91: Munro AW, Ritchie GY, Lamb AJ, Douglas RM, Booth IR (1991). "The cloning and DNA sequence of the gene for the glutathione-regulated potassium-efflux system KefC of Escherichia coli." Mol Microbiol 5(3);607-16. PMID: 2046548

Ness99: Ness LS, Booth IR (1999). "Different foci for the regulation of the activity of the KefB and KefC glutathione-gated K+ efflux systems." J Biol Chem 1999;274(14);9524-30. PMID: 10092637

Roosild09: Roosild TP, Castronovo S, Miller S, Li C, Rasmussen T, Bartlett W, Gunasekera B, Choe S, Booth IR (2009). "KTN (RCK) domains regulate K+ channels and transporters by controlling the dimer-hinge conformation." Structure 17(6);893-903. PMID: 19523906

Roosild10: Roosild TP, Castronovo S, Healy J, Miller S, Pliotas C, Rasmussen T, Bartlett W, Conway SJ, Booth IR (2010). "Mechanism of ligand-gated potassium efflux in bacterial pathogens." Proc Natl Acad Sci U S A 107(46);19784-9. PMID: 21041667

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProt10b: UniProt Consortium (2010). "UniProt version 2010-12 released on 2010-12-01 00:00:00." Database.

UniProt13: UniProt Consortium (2013). "UniProt version 2013-08 released on 2013-08-01 00:00:00." Database.

UniProt14: UniProt Consortium (2014). "UniProt version 2014-01 released on 2014-01-01 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 18.5 on Fri Dec 19, 2014, biocyc14.