Transport proteins

Mechanosensitive channels

• Channel of large conductance: MscL
• Channels of small conductance: YfkC, YhdY, YkuT
  • a mutant devoid of all four mechanosensitive channels (TMB99, Δ(mscL::spc) Δ(ykuT::cat) Δ(yhdY::ery) Δ(yfkC::kan)) is available in Erhard Bremer's lab PubMed

Ion transporters

Ion uptake

• potassium uptake: KtrA-KtrB, KtrC-KtrD

Ion export

• Na(+)/H(+) antiporter: MrpA-MrpB-MrpC-MrpD-MrpE-MrpF-MrpG
• monovalent cation (Na, K, Li, Rb)/H(+) antiporter: NhaK

ECF transporter for the uptake of micronutrients

• (YbxA-YbaE)-YbaF (general components)
• RibU
• ThiT
• YhfU
• TrpP

Amino acid uptake

• arginine: ArtP-ArtQ-ArtR
• branched-chain amino acids: BraB, BrnQ
• cystine: TcyA-TcyB-TcyC; TcyJ-TcyK-TcyL-TcyM-TcyN
• glutamate: GltP; GltP
• glutamine: GlnH-GlnM-GlnP-GlnQ
• methionine: MetN-MetP-MetQ
• proline: PutP
• tryptophan: (YbxA-YbaE)-YbaF-TrpP

Nucleotide and nucleoside transporters

Nucleotide and nucleoside uptake

• hypoxanthine/ guanine: PbuG
• hypoxanthine/ guanine: PbuO (based on similarity)

Nucleotide and nucleoside export

• hypoxanthine: PbuE (putative)

Sugar transport proteins

ABC transporters

• ATP-binding subunit for multiple ABC transporters: MsmX
• aminosugar uptake: YurJ-YurM-YurN-YurO
• arabinose uptake: AraN-AraP-AraQ
• galactotriose uptake: CycB-GanP-GanQ
• maltodextrin uptake: MdxE-MdxF-MdxG
• melibiose uptake: AmyC-AmyD-MsmE
• ribose uptake: RbsA-RbsB-RbsC-RbsD

PTS proteins

• General PTS proteins: Enzyme I, HPr
• PtsG: glucose permease, EIICBA
• GamP: glucosamine permease, EIICBA
• MurP: N-acetyl muramic acid-specific phosphotransferase system, EIIBC component
• MtlA, MtlF: mannitol permease
• GmuA, GmuB, GmuC: galactomannan permease
• TreP: trehalose permease
• MalP: maltose permease
• FruA: fructose permease
• ManP: mannose permease
• YpqE: unknown EIIA component
• LevD, LevE, LevF, LevG: fructose permease
• SacP: sucrose permease (high affinity)
• SacY: sucrose permease (low affinity)
• LicA, LicB, LicC: lichenan permease
• BglP: ß-glucoside permease
• YyzE: unknown PTS protein
• YwbA: unknown EIIC component

The PTS in SubtiPathways

• Central C-metabolism
• Sugar catabolism

Transporters for the uptake of compatible solutes in response to hyperosmolarity

• OpuAA-OpuAB-OpuAC: ABC transporter for glycine betaine
• OpuBA-OpuBB-OpuBC-OpuBD: ABC transporter for choline
• OpuCA-OpuCB-OpuCC-OpuCD: ABC transporter for glycine betaine/ carnitine/ choline
• OpuD: transporter for glycine betaine
• OpuE: transporter for proline

Uptake of siderophores

• petrobactin: YclN-YclO-YclP-YclQ

Related Lists

• ABC transporter, PTS

External Links

The Transporter Classification Database

Relevant Reviews

Ian R Booth, Paul Blount
The MscS and MscL families of mechanosensitive channels act as microbial emergency release valves.
J Bacteriol: 2012, 194(18);4802-9
[PubMed:22685280] [WorldCat.org] [DOI] (I p)

Ching Kung, Boris Martinac, Sergei Sukharev
Mechanosensitive channels in microbes.
Annu Rev Microbiol: 2010, 64;313-29
[PubMed:20825352] [WorldCat.org] [DOI] (I p)

Thomas Eitinger, Dmitry A Rodionov, Mathias Grote, Erwin Schneider
Canonical and ECF-type ATP-binding cassette importers in prokaryotes: diversity in modular organization and cellular functions.
FEMS Microbiol Rev: 2011, 35(1);3-67
[PubMed:20497229] [WorldCat.org] [DOI] (I p)

Christopher D Pivetti, Ming-Ren Yen, Samantha Miller, Wolfgang Busch, Yi-Hsiung Tseng, Ian R Booth, Milton H Saier
Two families of mechanosensitive channel proteins.
Microbiol Mol Biol Rev: 2003, 67(1);66-85, table of contents
[PubMed:12626684] [WorldCat.org] [DOI] (P p)

Milton H Saier, Seth R Goldman, Randal R Maile, Matthew S Moreno, Walter Weyler, Nelson Yang, Ian T Paulsen
Transport capabilities encoded within the Bacillus subtilis genome.
J Mol Microbiol Biotechnol: 2002, 4(1);37-67
[PubMed:11763970] [WorldCat.org] (P p)

Ralf Rabus, Donald L Jack, David J Kelly, Milton H Saier
TRAP transporters: an ancient family of extracytoplasmic solute-receptor-dependent secondary active transporters.
Microbiology (Reading): 1999, 145 ( Pt 12);3431-3445
[PubMed:10627041] [WorldCat.org] [DOI] (P p)

Jonathan Reizer, Steffi Bachem, Aiala Reizer, Maryvonne Arnaud, Milton H Saier, Jörg Stülke
Novel phosphotransferase system genes revealed by genome analysis - the complete complement of PTS proteins encoded within the genome of Bacillus subtilis.
Microbiology (Reading): 1999, 145 ( Pt 12);3419-3429
[PubMed:10627040] [WorldCat.org] [DOI] (P p)

Y Quentin, G Fichant, F Denizot
Inventory, assembly and analysis of Bacillus subtilis ABC transport systems.
J Mol Biol: 1999, 287(3);467-84
[PubMed:10092453] [WorldCat.org] [DOI] (P p)