ECF transporter

Parent categories	1. Cellular processes 1.2. Transporters
Neighbouring categories	1.2.1. ABC transporters 1.2.2. Phosphotransferase systems 1.2.3. ECF transporter 1.2.4. Transporters/ other
Related categories	transport proteins
Overview on the categories (Excel file) All genes and their categories (Excel file)

ECF transporters are required for the uptake of micronutrients such as cofactors (vitamins), metal ions, or amino acids. The transporters are composed of three general components (membrane spanning T protein und two ATP-hydrolyzing A proteins) and substrate-specific S proteins. In B. subtilis, there are four known substrates for ECF transporters, riboflavin, thiamine, biotin, and tryptophan.

The general components of the ECF transporters

• ybxA ATP-binding A1 protein (EcfA1)
• ybaE ATP-binding A2 protein (EcfA2)
• ybaF membrane-spanning T protein (EcfT)

The substrate-specific S components of the ECF transporters

• RibU: uptake of riboflavin
• ThiT: uptake of thiamine
• YhfU: uptake of biotin
• TrpP: uptake of tryptophan
• YuiG: unknown specificity, may also transport biotin

The class I ECF transporter for thiamine

• ThiU: binding protein
• ThiV: substrate-specific S component
• ThiW: ATP-binding protein (corresponds to A1 + A2)
• ThiX: membrane-spanning T protein

Important reviews and publications

Kaspar P Locher
Mechanistic diversity in ATP-binding cassette (ABC) transporters.
Nat Struct Mol Biol: 2016, 23(6);487-93
[PubMed:27273632] [WorldCat.org] [DOI] (I p)

Dirk J Slotboom
Structural and mechanistic insights into prokaryotic energy-coupling factor transporters.
Nat Rev Microbiol: 2014, 12(2);79-87
[PubMed:24362466] [WorldCat.org] [DOI] (I p)

Ke Xu, Minhua Zhang, Qin Zhao, Fang Yu, Hui Guo, Chengyuan Wang, Fangyuan He, Jianping Ding, Peng Zhang
Crystal structure of a folate energy-coupling factor transporter from Lactobacillus brevis.
Nature: 2013, 497(7448);268-71
[PubMed:23584589] [WorldCat.org] [DOI] (I p)

Guus B Erkens, Maria Majsnerowska, Josy ter Beek, Dirk Jan Slotboom
Energy coupling factor-type ABC transporters for vitamin uptake in prokaryotes.
Biochemistry: 2012, 51(22);4390-6
[PubMed:22574898] [WorldCat.org] [DOI] (I p)

Josy ter Beek, Ria H Duurkens, Guus B Erkens, Dirk Jan Slotboom
Quaternary structure and functional unit of energy coupling factor (ECF)-type transporters.
J Biol Chem: 2011, 286(7);5471-5
[PubMed:21135102] [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)

Dmitry A Rodionov, Peter Hebbeln, Aymerick Eudes, Josy ter Beek, Irina A Rodionova, Guus B Erkens, Dirk J Slotboom, Mikhail S Gelfand, Andrei L Osterman, Andrew D Hanson, Thomas Eitinger
A novel class of modular transporters for vitamins in prokaryotes.
J Bacteriol: 2009, 191(1);42-51
[PubMed:18931129] [WorldCat.org] [DOI] (I p)