scholarly journals Conformational and dynamic plasticity in substrate-binding proteins underlies selective transport in ABC importers

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Marijn de Boer ◽  
Giorgos Gouridis ◽  
Ruslan Vietrov ◽  
Stephanie L Begg ◽  
Gea K Schuurman-Wolters ◽  
...  

Substrate-binding proteins (SBPs) are associated with ATP-binding cassette importers and switch from an open to a closed conformation upon substrate binding, providing specificity for transport. We investigated the effect of substrates on the conformational dynamics of six SBPs and the impact on transport. Using single-molecule FRET, we reveal an unrecognized diversity of plasticity in SBPs. We show that a unique closed SBP conformation does not exist for transported substrates. Instead, SBPs sample a range of conformations that activate transport. Certain non-transported ligands leave the structure largely unaltered or trigger a conformation distinct from that of transported substrates. Intriguingly, in some cases, similar SBP conformations are formed by both transported and non-transported ligands. In this case, the inability for transport arises from slow opening of the SBP or the selectivity provided by the translocator. Our results reveal the complex interplay between ligand-SBP interactions, SBP conformational dynamics and substrate transport.

2019 ◽  
Author(s):  
Marijn de Boer ◽  
Giorgos Gouridis ◽  
Ruslan Vietrov ◽  
Stephanie L. Begg ◽  
Gea K. Schuurman-Wolters ◽  
...  

ABSTRACTSubstrate-binding proteins (SBPs) are associated with ATP-binding cassette importers and switch from an open-to a closed-conformation upon substrate binding providing specificity for transport. We investigated the effect of substrates on the conformational dynamics of six SBPs and the impact on transport. Using single-molecule FRET, we reveal an unrecognized diversity of plasticity in SBPs. We show that a unique closed SBP conformation does not exist for transported substrates. Instead, SBPs sample a range of conformations that activate transport. Certain non-transported ligands leave the structure largely unaltered or trigger a conformation distinct from that of transported substrates. Intriguingly, in some cases similar SBP conformations are formed by both transported and non-transported ligands. In this case, the inability for transport arises from slow opening of the SBP or the selectivity provided by the translocator. Our results reveal the complex interplay between ligand-SBP interactions, SBP conformational dynamics and substrate transport.


2019 ◽  
Author(s):  
Marijn de Boer ◽  
Giorgos Gouridis ◽  
Ruslan Vietrov ◽  
Stephanie L Begg ◽  
Gea K Schuurman-Wolters ◽  
...  

2018 ◽  
Author(s):  
Alexander Carl DeHaven

This thesis contains four topic areas: a review of single-molecule microscropy methods and splicing, conformational dynamics of stem II of the U2 snRNA, the impact of post-transcriptional modifications on U2 snRNA folding dynamics, and preliminary findings on Mango aptamer folding dynamics.


2018 ◽  
Vol 115 (45) ◽  
pp. 11525-11530 ◽  
Author(s):  
Marcelo E. Guerin ◽  
Guillaume Stirnemann ◽  
David Giganti

An immense repertoire of protein chemical modifications catalyzed by enzymes is available as proteomics data. Quantifying the impact of the conformational dynamics of the modified peptide remains challenging to understand the decisive kinetics and amino acid sequence specificity of these enzymatic reactions in vivo, because the target peptide must be disordered to accommodate the specific enzyme-binding site. Here, we were able to control the conformation of a single-molecule peptide chain by applying mechanical force to activate and monitor its specific cleavage by a model protease. We found that the conformational entropy impacts the reaction in two distinct ways. First, the flexibility and accessibility of the substrate peptide greatly increase upon mechanical unfolding. Second, the conformational sampling of the disordered peptide drives the specific recognition, revealing force-dependent reaction kinetics. These results support a mechanism of peptide recognition based on conformational selection from an ensemble that we were able to quantify with a torsional free-energy model. Our approach can be used to predict how entropy affects site-specific modifications of proteins and prompts conformational and mechanical selectivity.


2013 ◽  
Vol 117 (50) ◽  
pp. 16105-16109 ◽  
Author(s):  
Roman Tsukanov ◽  
Toma E. Tomov ◽  
Yaron Berger ◽  
Miran Liber ◽  
Eyal Nir

2018 ◽  
Vol 37 (21) ◽  
Author(s):  
Florence Husada ◽  
Kiran Bountra ◽  
Konstantinos Tassis ◽  
Marijn Boer ◽  
Maria Romano ◽  
...  

2011 ◽  
Vol 100 (3) ◽  
pp. 474a-475a
Author(s):  
Markus Richert ◽  
Dymitro Rodnin ◽  
Carola S. Hengstenberg ◽  
Thomas Peulen ◽  
Alessandro Valeri ◽  
...  

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