scholarly journals Structural basis for the binding of SNAREs to the multisubunit tethering complex Dsl1

2020 ◽  
Author(s):  
Sophie M. Travis ◽  
Kevin DAmico ◽  
I-Mei Yu ◽  
Safraz Hamid ◽  
Gabriel Ramirez-Arellano ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Relative Orientation ◽  
Snare Complex ◽  
Structural Basis ◽  
Binding Modes ◽  
Range Interaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Long Range Interaction ◽  
Target Membrane

AbstractMultisubunit tethering complexes (MTCs) are large (250 to >750 kDa), conserved macromolecular machines that are essential for SNARE-mediated membrane fusion in all eukaryotes. MTCs are thought to function as organizers of membrane trafficking, mediating the initial, long-range interaction between a vesicle and its target membrane and promoting the formation of membrane-bridging SNARE complexes. Previously, we reported the structure of the Dsl1 complex, the simplest known MTC, which is essential for COPI-mediated transport from the Golgi to the endoplasmic reticulum (ER). This structure suggested how the Dsl1 complex might function to tether a vesicle to its target membrane by binding at one end to the COPI coat and at the other end to ER SNAREs. Here, we use x-ray crystallography to investigate these Dsl1-SNARE interactions in greater detail. The Dsl1 complex comprises three subunits that together form a two-legged structure with a central hinge. Our results show that distal regions of each leg bind N-terminal Habc domains of the ER SNAREs Sec20 (a Qb-SNARE) and Use1 (a Qc-SNARE). The observed binding modes appear to anchor the Dsl1 complex to the ER target membrane while simultaneously ensuring that both SNAREs are in open conformations with their SNARE motifs available for assembly. The proximity of the two SNARE motifs, and therefore their ability to enter the same SNARE complex, depends on the relative orientation of the two Dsl1 legs.

scholarly journals Structural basis for the binding of SNAREs to the multisubunit tethering complex Dsl1

2020 ◽  
Vol 295 (30) ◽  
pp. 10125-10135 ◽  
Author(s):  
Sophie M. Travis ◽  
Kevin DAmico ◽  
I-Mei Yu ◽  
Conor McMahon ◽  
Safraz Hamid ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Snare Complex ◽  
Structural Basis ◽  
Binding Modes ◽  
Range Interaction ◽  
Vesicle Docking ◽  
X Ray Crystallography ◽  
Protein Receptor ◽  
Long Range Interaction ◽  
Target Membrane

Multisubunit-tethering complexes (MTCs) are large (250 to >750 kDa), conserved macromolecular machines that are essential for soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE)–mediated membrane fusion in all eukaryotes. MTCs are thought to organize membrane trafficking by mediating the initial long-range interaction between a vesicle and its target membrane and promoting the formation of membrane-bridging SNARE complexes. Previously, we reported the structure of the yeast Dsl1 complex, the simplest known MTC, which is essential for coat protein I (COPI) mediated transport from the Golgi to the endoplasmic reticulum (ER). This structure suggests how the Dsl1 complex might tether a vesicle to its target membrane by binding at one end to the COPI coat and at the other to ER-associated SNAREs. Here, we used X-ray crystallography to investigate these Dsl1–SNARE interactions in greater detail. The Dsl1 complex comprises three subunits that together form a two-legged structure with a central hinge. We found that distal regions of each leg bind N-terminal Habc domains of the ER SNAREs Sec20 (a Qb-SNARE) and Use1 (a Qc-SNARE). The observed binding modes appear to anchor the Dsl1 complex to the ER target membrane while simultaneously ensuring that both SNAREs are in open conformations, with their SNARE motifs available for assembly. The proximity of the two SNARE motifs, and therefore their ability to enter the same SNARE complex, will depend on the relative orientation of the two Dsl1 legs. These results underscore the critical roles of SNARE N-terminal domains in mediating interactions with other elements of the vesicle docking and fusion machinery.

scholarly journals Dual roles of Munc18-1 rely on distinct binding modes of the central cavity with Stx1A and SNARE complex

2011 ◽  
Vol 22 (21) ◽  
pp. 4150-4160 ◽  
Author(s):  
Lei Shi ◽  
Daniel Kümmel ◽  
Jeff Coleman ◽  
Thomas J. Melia ◽  
Claudio G. Giraudo
Keyword(s):  
Membrane Trafficking ◽  
Molecular Mechanisms ◽  
Neuroendocrine Cells ◽  
Snare Complex ◽  
Binding Modes ◽  
Central Cavity ◽  
Syntaxin 1A ◽  
Chaperone Function ◽  
Protein Receptors ◽  
Liposome Fusion

Sec1/Munc18 proteins play a fundamental role in multiple steps of intracellular membrane trafficking. Dual functions have been attributed to Munc18-1: it can act as a chaperone when it interacts with monomeric syntaxin 1A, and it can activate soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) for membrane fusion when it binds to SNARE complexes. Although both modes of binding involve the central cavity of Munc18-1, their precise molecular mechanisms of action are not fully understood. In this paper, we describe a novel Munc18-1 mutant in the central cavity that showed a reduced interaction with syntaxin 1A and impaired chaperone function, but still bound to assembled SNARE complexes and promoted liposome fusion and secretion in neuroendocrine cells. Soluble syntaxin 1A H3 domain partially blocks Munc18-1 activation of liposome fusion by occupying the Munc18-1 central cavity. Our findings lead us to propose a transition model between the two distinct binding modes by which Munc18 can control and assist in SNARE-complex assembly during neurotransmitter release.

scholarly journals Multiple binding modes of a small molecule to human Keap1 revealed by X-ray crystallography and molecular dynamics simulation

FEBS Open Bio ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 557-570 ◽  
Author(s):  
Mikiya Satoh ◽  
Hajime Saburi ◽  
Tomoyuki Tanaka ◽  
Yoshinori Matsuura ◽  
Hisashi Naitow ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Small Molecule ◽  
Dynamics Simulation ◽  
Binding Modes ◽  
X Ray ◽  
X Ray Crystallography ◽  
Multiple Binding

scholarly journals The dimensions and shapes of the furanose rings in nucleic acids

1972 ◽  
Vol 130 (2) ◽  
pp. 453-465 ◽  
Author(s):  
S. Arnott ◽  
D. W. L. Hukins
Keyword(s):  
Nucleic Acids ◽  
Model Building ◽  
Molecular Model ◽  
Relative Orientation ◽  
Ring Conformation ◽  
Mean Values ◽  
Pyrimidine Base ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ring Puckering

A survey was made of the geometry of furanose rings in β-nucleotides and β-nucleosides (as monomers related to nucleic acids) for which structures have been determined by X-ray crystallography. Mean values, and estimated standard deviations from them, were calculated for bond-lengths, bond-angles and conformation-angles. For parameters with values dependent on ring-puckering, separate calculations were made for each ring type. (The rings are puckered in one of three conformations: C-2- or C-3-endo or C-3-exo; C-2-exo has not been observed.) The results were used to compute standard furanose rings with C-2-endo, C-3-endo and C-3-exo conformations for use in nucleic acid molecular model-building. The survey also showed that the only other conformation-angle in nucleotides dependent on the furanose ring conformation corresponds to the relative orientation of the purine (or pyrimidine) base and the ring.

scholarly journals X-Ray Crystallography and Free Energy Calculations Reveal the Binding Mechanism of A2A Adenosine Receptor Antagonists

2019 ◽  
Author(s):  
Willem Jespers ◽  
Grégory Verdon ◽  
Jhonny Azuaje ◽  
maria majellaro ◽  
Henrik Keränen ◽  
...  
Keyword(s):  
Free Energy ◽  
Adenosine Receptor ◽  
Free Energy Calculations ◽  
Binding Modes ◽  
A2a Adenosine Receptor ◽  
Binding Model ◽  
Energy Calculations ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pharmacological Data

<div> <div> <div> <p>Nowadays, rigorous free energy calculations are routinely considered in pharmaceutical design strategies. One typical sce- nario is the lead-optimization based on well-defined protein-ligand binding modes, inferred by pharmacological data in com- putational models and ultimately revealed by structural data. In this work, we reveal the molecular determinants of antago- nist binding to the adenosine A2A adenosine receptor (AR), an emerging target in immuno-oncology, via a robust protocol that connects structural and pharmacological data through free energy perturbation (FEP) calculations. Eight A2AAR binding site mutations from biophysical mapping experiments were initially analyzed with FEP simulations of each side-chain mutation, performed on alternate binding modes previously proposed in the literature. The results strongly suggested that only one binding mode could explain this experimental data, which was used to subsequently design a series of 11 chromone deriva- tives. The experimental affinities of these new compounds were linked through a cycle of ligand-FEP calculations around selected ligand pairs, which allowed the identification of the optimal positioning of the different chemical substituents in the proposed binding model. Subsequent X-ray crystallography of the A2AAR with a low and high affinity chromone derivative confirmed the predicted binding orientation, and provided new insights in the role of the explored substituents in the chro- </p> </div> </div> <div> <div> <p>mone scaffold. </p> </div> </div> </div>

scholarly journals Structural basis for DNA recognition and allosteric control of the retinoic acid receptors RAR–RXR

2020 ◽  
Vol 48 (17) ◽  
pp. 9969-9985
Author(s):  
Judit Osz ◽  
Alastair G McEwen ◽  
Maxime Bourguet ◽  
Frédéric Przybilla ◽  
Carole Peluso-Iltis ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Dna Binding ◽  
Structural Dynamics ◽  
Binding Domain ◽  
Retinoic Acid Receptors ◽  
Structural Basis ◽  
Dna Binding Domain ◽  
Binding Modes ◽  
Dna Complexes ◽  
X Ray

Abstract Retinoic acid receptors (RARs) as a functional heterodimer with retinoid X receptors (RXRs), bind a diverse series of RA-response elements (RAREs) in regulated genes. Among them, the non-canonical DR0 elements are bound by RXR–RAR with comparable affinities to DR5 elements but DR0 elements do not act transcriptionally as independent RAREs. In this work, we present structural insights for the recognition of DR5 and DR0 elements by RXR–RAR heterodimer using x-ray crystallography, small angle x-ray scattering, and hydrogen/deuterium exchange coupled to mass spectrometry. We solved the crystal structures of RXR–RAR DNA-binding domain in complex with the Rarb2 DR5 and RXR–RXR DNA-binding domain in complex with Hoxb13 DR0. While cooperative binding was observed on DR5, the two molecules bound non-cooperatively on DR0 on opposite sides of the DNA. In addition, our data unveil the structural organization and dynamics of the multi-domain RXR–RAR DNA complexes providing evidence for DNA-dependent allosteric communication between domains. Differential binding modes between DR0 and DR5 were observed leading to differences in conformation and structural dynamics of the multi-domain RXR–RAR DNA complexes. These results reveal that the topological organization of the RAR binding element confer regulatory information by modulating the overall topology and structural dynamics of the RXR–RAR heterodimers.

scholarly journals Comparison of Orexin 1 and Orexin 2 Ligand Binding Modes Using X-ray Crystallography and Computational Analysis

2019 ◽  
Vol 63 (4) ◽  
pp. 1528-1543 ◽  
Author(s):  
Mathieu Rappas ◽  
Ammar A. E. Ali ◽  
Kirstie A. Bennett ◽  
Jason D. Brown ◽  
Sarah J. Bucknell ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Computational Analysis ◽  
Binding Modes ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Crystal structure of glycosyltrehalose synthase fromSulfolobus shibataeDSM5389

2018 ◽  
Vol 74 (11) ◽  
pp. 741-746
Author(s):  
Nobuo Okazaki ◽  
Michael Blaber ◽  
Ryota Kuroki ◽  
Taro Tamada
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Catalytic Mechanism ◽  
Catalytic Domain ◽  
Structural Basis ◽  
Hyperthermophilic Archaeon ◽  
X Ray ◽  
X Ray Crystallography ◽  
Sulfolobus Shibatae ◽  
Glucosidic Bond

Glycosyltrehalose synthase (GTSase) converts the glucosidic bond between the last two glucose residues of amylose from an α-1,4 bond to an α-1,1 bond, generating a nonreducing glycosyl trehaloside, in the first step of the biosynthesis of trehalose. To better understand the structural basis of the catalytic mechanism, the crystal structure of GTSase from the hyperthermophilic archaeonSulfolobus shibataeDSM5389 (5389-GTSase) has been determined to 2.4 Å resolution by X-ray crystallography. The structure of 5389-GTSase can be divided into five domains. The central domain contains the (β/α)8-barrel fold that is conserved as the catalytic domain in the α-amylase family. Three invariant catalytic carboxylic amino acids in the α-amylase family are also found in GTSase at positions Asp241, Glu269 and Asp460 in the catalytic domain. The shape of the catalytic cavity and the pocket size at the bottom of the cavity correspond to the intramolecular transglycosylation mechanism proposed from previous enzymatic studies.

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