scholarly journals ECF-Type ATP-Binding Cassette Transporters

2019 ◽  
Vol 88 (1) ◽  
pp. 551-576 ◽  
Author(s):  
S. Rempel ◽  
W.K. Stanek ◽  
D.J. Slotboom
Keyword(s):  
Biochemical Characterization ◽  
Structural Data ◽  
Energy Coupling ◽  
Coupling Factor ◽  
Transport Systems ◽  
Power Stroke ◽  
Atp Binding ◽  
Abc Transport ◽  
Extracellular Side ◽  
Atp Binding Cassette

Energy-coupling factor (ECF)–type ATP-binding cassette (ABC) transporters catalyze membrane transport of micronutrients in prokaryotes. Crystal structures and biochemical characterization have revealed that ECF transporters are mechanistically distinct from other ABC transport systems. Notably, ECF transporters make use of small integral membrane subunits (S-components) that are predicted to topple over in the membrane when carrying the bound substrate from the extracellular side of the bilayer to the cytosol. Here, we review the phylogenetic diversity of ECF transporters as well as recent structural and biochemical advancements that have led to the postulation of conceptually different mechanistic models. These models can be described as power stroke and thermal ratchet. Structural data indicate that the lipid composition and bilayer structure are likely to have great impact on the transport function. We argue that study of ECF transporters could lead to generic insight into membrane protein structure, dynamics, and interaction.

scholarly journals Biochemical evidence for the presence of two α-glucoside ABC-transport systems in the hyperthermophilic archaeonPyrococcus furiosus

Archaea ◽  
2002 ◽  
Vol 1 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Sonja M. Koning ◽  
Wil N. Konings ◽  
Arnold J.M. Driessen
Keyword(s):  
Transport System ◽  
Pyrococcus Furiosus ◽  
Binding Protein ◽  
Transport Systems ◽  
Atp Binding ◽  
Hyperthermophilic Archaeon ◽  
Biochemical Evidence ◽  
Abc Transport ◽  
Maltose Transporter ◽  
Atp Binding Cassette

The hyperthermophilic archaeonPyrococcus furiosuscan utilize different carbohydrates, such as starch, maltose and trehalose. Uptake of α-glucosides is mediated by two different, binding protein-dependent, ATP-binding cassette (ABC)-type transport systems. The maltose transporter also transports trehalose, whereas the maltodextrin transport system mediates the uptake of maltotriose and higher malto-oligosaccharides, but not maltose. Both transport systems are induced during growth on their respective substrates.

scholarly journals ATP-binding Cassette Transporters Are Required for Efficient RNA Interference in Caenorhabditis elegans

2006 ◽  
Vol 17 (8) ◽  
pp. 3678-3688 ◽  
Author(s):  
Prema Sundaram ◽  
Benjamin Echalier ◽  
Wang Han ◽  
Dawn Hull ◽  
Lisa Timmons
Keyword(s):  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Abc Transporters ◽  
Transport Systems ◽  
Atp Binding ◽  
C Elegans ◽  
Steep Concentration Gradient ◽  
Conserved Gene ◽  
Membrane Transport Systems ◽  
Atp Binding Cassette

RNA interference (RNAi) is a conserved gene-silencing phenomenon that can be triggered by delivery of double-stranded RNA (dsRNA) to cells and is a widely exploited technology in analyses of gene function. Although a number of proteins that facilitate RNAi have been identified, current descriptions of RNAi and interrelated mechanisms are far from complete. Here, we report that the Caenorhabditis elegans gene haf-6 is required for efficient RNAi. HAF-6 is a member of the ATP-binding cassette (ABC) transporter gene superfamily. ABC transporters use ATP to translocate small molecule substrates across the membranes in which they reside, often against a steep concentration gradient. Collectively, ABC transporters are involved in a variety of activities, including protective or barrier mechanisms that export drugs or toxins from cells, organellar biogenesis, and mechanisms that protect against viral infection. HAF-6 is expressed predominantly in the intestine and germline and is localized to intracellular reticular organelles. We further demonstrate that eight additional ABC genes from diverse subfamilies are each required for efficient RNAi in C. elegans. Thus, the ability to mount a robust RNAi response to dsRNA depends upon the deployment of two ancient systems that respond to environmental assaults: RNAi mechanisms and membrane transport systems that use ABC proteins.

scholarly journals Localization of the ATP-binding cassette (ABC) transport proteins PfMRP1, PfMRP2, and PfMDR5 at the Plasmodium falciparum plasma membrane

2009 ◽  
Vol 8 (1) ◽  
pp. 205 ◽  
Author(s):  
Reginald A Kavishe ◽  
Jeroen MW van den Heuvel ◽  
Marga van de Vegte-Bolmer ◽  
Adrian JF Luty ◽  
Frans GM Russel ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Transport Proteins ◽  
Atp Binding ◽  
Abc Transport ◽  
Atp Binding Cassette

Periplasmic binding protein-dependent transport systems: the membrane-associated components

1990 ◽  
Vol 326 (1236) ◽  
pp. 353-365 ◽  
Keyword(s):  
Transport System ◽  
Atp Hydrolysis ◽  
Binding Protein ◽  
Primary Source ◽  
Energy Coupling ◽  
Transport Systems ◽  
Common Mechanism ◽  
Atp Binding ◽  
Periplasmic Binding Protein ◽  
Dependent Transport

Periplasmic binding protein-dependent transport systems are multicomponent, consisting of several inner membrane-associated proteins and a periplasmic component. The membrane-associated components of different systems are related in organization and function suggesting that, despite different substrate specificities, each transport system functions by a common mechanism. Current understanding of these components is reviewed. The nature of energy coupling to periplasmic transport systems has long been debated. Recent data now demonstrate that ATP hydrolysis is the primary source of energy for transport. The ATP-binding transport components are the best characterized of a family of closely related ATP-binding proteins believed to couple ATP hydrolysis to a variety of different biological processes. Intriguingly, systems closely related to periplasmic binding protein-dependent transport systems have recently been identified in several Gram-positive organisms (which lack a periplasm) and in eukaryotic cells. This class of transport system appears to be widespread in nature, serving a variety of important and diverse functions.

scholarly journals An Operon for a Putative ATP-Binding Cassette Transport System Involved in Acetoin Utilization ofBacillus subtilis

2000 ◽  
Vol 182 (19) ◽  
pp. 5454-5461 ◽  
Author(s):  
Ken-Ichi Yoshida ◽  
Yasutaro Fujita ◽  
S. Dusko Ehrlich
Keyword(s):  
Stationary Phase ◽  
Transport System ◽  
Minimal Medium ◽  
Atp Binding ◽  
Ofbacillus Subtilis ◽  
Abc Transport ◽  
Maximum Cell ◽  
Highly Hydrophobic ◽  
Single Operon ◽  
Atp Binding Cassette

ABSTRACT The ytrABCDEF operon of Bacillus subtiliswas deduced to encode a putative ATP-binding cassette (ABC) transport system. YtrB and YtrE could be the ABC subunits, and YtrC and YtrD are highly hydrophobic and could form a channel through the cell membrane, while YtrF could be a periplasmic lipoprotein for substrate binding. Expression of the operon was examined in cells grown in a minimal medium. The results indicate that the expression was induced only early in the stationary phase. The six ytr genes form a single operon, transcribed from a putative ςA-dependent promoter present upstream of ytrA. YtrA, which possesses a helix-turn-helix motif of the GntR family, acts probably as a repressor and regulates its own transcription. Inactivation of the operon led to a decrease in maximum cell yield and less-efficient sporulation, suggesting its involvement in the growth in stationary phase and sporulation. It is known that B. subtilis produces acetoin as an external carbon storage compound and then reuses it later during stationary phase and sporulation. When either the entireytr operon or its last gene, ytrF, was inactivated, the production of acetoin was not affected, but the reuse of acetoin became less efficient. We suggest that the Ytr transport system plays a role in acetoin utilization during stationary phase and sporulation.

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