The Engine of ABC Proteins

Physiology ◽  
2003 ◽  
Vol 18 (5) ◽  
pp. 191-195 ◽  
Author(s):  
Guillermo A. Altenberg
Keyword(s):  
Molecular Mechanism ◽  
Nucleotide Binding ◽  
Atp Binding ◽  
Protein Families ◽  
Abc Proteins ◽  
Substrate Transport ◽  
Binding Domains ◽  
Atp Binding Cassette

Proteins that belong to the ATP-binding cassette superfamily span from bacteria to humans and comprise one of the largest protein families. These proteins are characterized by the presence of two nucleotide-binding domains, and recent studies suggest that association and dissociation of these domains is a common basic molecular mechanism of operation that couples ATP binding/hydrolysis to substrate transport across membranes.

scholarly journals Association/Dissociation of the Nucleotide-binding Domains of the ATP-binding Cassette Protein MsbA Measured during Continuous Hydrolysis

2013 ◽  
Vol 288 (29) ◽  
pp. 20785-20796 ◽  
Author(s):  
Rebecca S. Cooper ◽  
Guillermo A. Altenberg
Keyword(s):  
Atp Hydrolysis ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Nucleotide Binding ◽  
Atp Binding ◽  
Binding Domains ◽  
Partial Opening ◽  
Contact Models ◽  
Bacterial Lipid ◽  
Atp Binding Cassette

In ATP-binding cassette proteins, the two nucleotide-binding domains (NBDs) work as dimers to bind and hydrolyze ATP, but the molecular mechanism of nucleotide hydrolysis is controversial. It is still unresolved whether hydrolysis leads to dissociation of the ATP-induced dimers or partial opening of the dimers such that the NBDs remain in contact during the hydrolysis cycle. We studied the bacterial lipid flippase MsbA by luminescence resonance energy transfer (LRET). The LRET signal between optical probes reacted with single-cysteine mutants was employed to follow NBD association/dissociation in real time. The intermonomer distances calculated from LRET data indicate that the NBDs separate completely following ATP hydrolysis, even in the presence of mm MgATP, and that the dissociation occurs following each hydrolysis cycle. The results support association/dissociation, as opposed to constant contact models, for the mode of operation of ATP-binding cassette proteins.

Nucleotide dependence of the dimerization of ATP binding cassette nucleotide binding domains

2016 ◽  
Vol 480 (2) ◽  
pp. 268-272 ◽  
Author(s):  
Gregory A. Fendley ◽  
Ina L. Urbatsch ◽  
Roger B. Sutton ◽  
Maria E. Zoghbi ◽  
Guillermo A. Altenberg
Keyword(s):  
Nucleotide Binding ◽  
Atp Binding ◽  
Binding Domains ◽  
Atp Binding Cassette

scholarly journals Domain Interactions in the Yeast ATP Binding Cassette Transporter Ycf1p: Intragenic Suppressor Analysis of Mutations in the Nucleotide Binding Domains

2001 ◽  
Vol 183 (16) ◽  
pp. 4761-4770 ◽  
Author(s):  
Juan M. Falcón-Pérez ◽  
Mónica Martı́nez-Burgos ◽  
Jesús Molano ◽  
Marı́a J. Mazón ◽  
Pilar Eraso
Keyword(s):  
Atpase Activity ◽  
Abc Transporter ◽  
Transmembrane Domain ◽  
Substrate Binding ◽  
Nucleotide Binding ◽  
Intramolecular Interactions ◽  
Phenotypic Characterization ◽  
Atp Binding ◽  
Binding Domains ◽  
Atp Binding Cassette

ABSTRACT The yeast cadmium factor (Ycf1p) is a vacuolar ATP binding cassette (ABC) transporter required for heavy metal and drug detoxification. Cluster analysis shows that Ycf1p is strongly related to the human multidrug-associated protein (MRP1) and cystic fibrosis transmembrane conductance regulator and therefore may serve as an excellent model for the study of eukaryotic ABC transporter structure and function. Identifying intramolecular interactions in these transporters may help to elucidate energy transfer mechanisms during transport. To identify regions in Ycf1p that may interact to couple ATPase activity to substrate binding and/or movement across the membrane, we sought intragenic suppressors of ycf1 mutations that affect highly conserved residues presumably involved in ATP binding and/or hydrolysis. Thirteen intragenic second-site suppressors were identified for the D777N mutation which affects the invariant Asp residue in the Walker B motif of the first nucleotide binding domain (NBD1). Two of the suppressor mutations (V543I and F565L) are located in the first transmembrane domain (TMD1), nine (A1003V, A1021T, A1021V, N1027D, Q1107R, G1207D, G1207S, S1212L, and W1225C) are found within TMD2, one (S674L) is in NBD1, and another one (R1415G) is in NBD2, indicating either physical proximity or functional interactions between NBD1 and the other three domains. The original D777N mutant protein exhibits a strong defect in the apparent affinity for ATP and V max of transport. The phenotypic characterization of the suppressor mutants shows that suppression does not result from restoring these alterations but rather from a change in substrate specificity. We discuss the possible involvement of Asp777 in coupling ATPase activity to substrate binding and/or transport across the membrane.

scholarly journals Functional hot spots in human ATP-binding cassette transporter nucleotide binding domains

2010 ◽  
Vol 19 (11) ◽  
pp. 2110-2121 ◽  
Author(s):  
Libusha Kelly ◽  
Hisayo Fukushima ◽  
Rachel Karchin ◽  
Jason M. Gow ◽  
Leslie W. Chinn ◽  
...  
Keyword(s):  
Hot Spots ◽  
Nucleotide Binding ◽  
Atp Binding ◽  
Binding Domains ◽  
Atp Binding Cassette Transporter ◽  
Atp Binding Cassette

scholarly journals Interaction between ATP, oleandomycin and the OleB ATP-binding cassette transporter of Streptomyces antibioticus involved in oleandomycin secretion

1997 ◽  
Vol 321 (1) ◽  
pp. 139-144 ◽  
Author(s):  
André BUCHE ◽  
Carmen MÉNDEZ ◽  
José A. SALAS
Keyword(s):  
Fusion Protein ◽  
Nucleotide Binding ◽  
Intrinsic Fluorescence ◽  
Atp Binding ◽  
Hydrophobic Membrane ◽  
Streptomyces Antibioticus ◽  
Binding Domains ◽  
Atp Binding Cassette Transporter ◽  
Guanidine Chloride ◽  
Atp Binding Cassette

The OleB protein of Streptomyces antibioticus, oleandomycin (OM) producer, constitutes an ATP-binding cassette transporter containing two nucleotide-binding domains and is involved in OM resistance and its secretion in this producer strain. We have characterized some properties of the first nucleotide-binding domain of OleB using an overexpressed fusion protein (MBP–OleB´) between a maltose-binding protein (MBP) and the first half of OleB (OleB´). Extrinsic fluorescence of the base-modified fluorescent nucleotide analogue 1,N6-ethenoadenosine 5´-triphosphate (εATP) and 2´(3´)-o-(2,4,6-trinitrophenyl)adenosine-5´-triphosphate was determined in the presence of MBP and the fusion protein MBP–OleB´, and it was found that εATP binds to MBP–OleB´ with a stoichiometry of 0.9. Measurements of the intrinsic fluorescence of the MBP–OleB´ fusion protein indicated that ATP induces a decrease in the accessibility of the MBP–OleB´ tryptophans to acrylamide, an indication of a folding effect. This conclusion was confirmed by the fact that ATP also induces considerable stabilization against guanidine chloride denaturation of MBP–OleB´. Two effects were found to be associated with the presence of Mg2+ ions: (1) an increase in the quenching of MBP–OleB´ intrinsic fluorescence by ATP; and (2) an increase in the accessibility of MBP–OleB´ tryptophans to acrylamide. Significant changes in the intrinsic fluorescence of the fusion protein were also observed in the presence of OM, demostrating the existence of interaction between the transporter and the antibiotic in the absence of any hydrophobic membrane component.

scholarly journals The Hydrolysis Cycle of ATP-Binding Cassette Nucleotide-Binding Domains

2015 ◽  
Vol 108 (2) ◽  
pp. 197a-198a
Author(s):  
Srinivasan Krishnan ◽  
Maria E. Zoghbi ◽  
Guillermo A. Altenberg
Keyword(s):  
Nucleotide Binding ◽  
Atp Binding ◽  
Binding Domains ◽  
Atp Binding Cassette

ATP-binding Cassette Exporters: Structure and Mechanism with a Focus on P-glycoprotein and MRP1

2019 ◽  
Vol 26 (7) ◽  
pp. 1062-1078 ◽  
Author(s):  
Maite Rocío Arana ◽  
Guillermo Alejandro Altenberg
Keyword(s):  
Binding Site ◽  
Conformational Changes ◽  
Structural Information ◽  
Nucleotide Binding ◽  
Binding Pocket ◽  
Atp Binding ◽  
Binding Domains ◽  
P Glycoprotein ◽  
And Function ◽  
Atp Binding Cassette

Background:Proteins that belong to the ATP-binding cassette superfamily include transporters that mediate the efflux of substrates from cells. Among these exporters, P-glycoprotein and MRP1 are involved in cancer multidrug resistance, protection from endo and xenobiotics, determination of drug pharmacokinetics, and the pathophysiology of a variety of disorders. Objective:To review the information available on ATP-binding cassette exporters, with a focus on Pglycoprotein, MRP1 and related proteins. We describe tissue localization and function of these transporters in health and disease, and discuss the mechanisms of substrate transport. We also correlate recent structural information with the function of the exporters, and discuss details of their molecular mechanism with a focus on the nucleotide-binding domains. Methods: Evaluation of selected publications on the structure and function of ATP-binding cassette proteins. Conclusions:Conformational changes on the nucleotide-binding domains side of the exporters switch the accessibility of the substrate-binding pocket between the inside and outside, which is coupled to substrate efflux. However, there is no agreement on the magnitude and nature of the changes at the nucleotide- binding domains side that drive the alternate-accessibility. Comparison of the structures of Pglycoprotein and MRP1 helps explain differences in substrate selectivity and the bases for polyspecificity. P-glycoprotein substrates are hydrophobic and/or weak bases, and polyspecificity is explained by a flexible hydrophobic multi-binding site that has a few acidic patches. MRP1 substrates are mostly organic acids, and its polyspecificity is due to a single bipartite binding site that is flexible and displays positive charge.

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