Structural Comparison of Ligand-Binding Domains in Estrogen-Related Receptors

2005 ◽  
Vol 277-279 ◽  
pp. 107-112
Author(s):  
Hye Yeon Kim ◽  
Ae Nim Pae ◽  
Yeon Joo Lee ◽  
Joon Kyu Park ◽  
Dae Sung Kim ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Model Building ◽  
Homology Model ◽  
Docking Studies ◽  
Antagonistic Effect ◽  
Orphan Nuclear Receptors ◽  
Binding Domains ◽  
Binding Pockets ◽  
Significant Amino Acid Sequence ◽  
Significant Amino Acid

Estrogen-related receptors (ERRs), orphan nuclear receptors, share a significant amino acid sequence homology with estrogen receptors (ERs), yet their ligands do not respond in the same manner. In fact, some of the ligands that are known as agonists of ERs show antagonistic effect in ERRs. Accordingly, the current study investigated the structures of the ligand-binding domains using homology model building and docking studies. The results showed clear differences between the ligand-binding pockets of ERRs and ERs, thereby providing structural insights into the activities related to the ligands.

scholarly journals A l-Lysine Transporter of High Stereoselectivity of the Amino Acid-Polyamine-Organocation (APC) Superfamily

2013 ◽  
Vol 289 (3) ◽  
pp. 1377-1387 ◽  
Author(s):  
Jagdeep Kaur ◽  
Elena Olkhova ◽  
Viveka Nand Malviya ◽  
Ernst Grell ◽  
Hartmut Michel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ligand Binding ◽  
Isothermal Titration Calorimetry ◽  
Functional Characterization ◽  
Homology Model ◽  
Docking Studies ◽  
Site Directed Mutagenesis ◽  
Titration Calorimetry ◽  
Amino Acid Residues

Membrane proteins of the amino acid-polyamine-organocation (APC) superfamily transport amino acids and amines across membranes and play an important role in the regulation of cellular processes. We report the heterologous production of the LysP-related transporter STM2200 from Salmonella typhimurium in Escherichia coli, its purification, and functional characterization. STM2200 is assumed to be a proton-dependent APC transporter of l-lysine. The functional interaction between basic amino acids and STM2200 was investigated by thermoanalytical methods, i.e. differential scanning and isothermal titration calorimetry. Binding of l-lysine to STM2200 in its solubilized monomer form is entropy-driven. It is characterized by a dissociation constant of 40 μm at pH 5.9 and is highly selective; no evidence was found for the binding of l-arginine, l-ornithine, l-2,4-diaminobutyric acid, and l-alanine. d-Lysine is bound 45 times more weakly than its l-chiral form. We thus postulate that STM2200 functions as a specific transport protein. Based on the crystal structure of ApcT (Shaffer, P. L., Goehring, A., Shankaranarayanan, A., and Gouaux, E. (2009) Science 325, 1010–1014), a proton-dependent amino acid transporter of the APC superfamily, a homology model of STM2200 was created. Docking studies allowed identification of possible ligand binding sites. The resulting predictions indicated that Glu-222 and Arg-395 of STM2200 are markedly involved in ligand binding, whereas Lys-163 is suggested to be of structural and functional relevance. Selected variants of STM2200 where these three amino acid residues were substituted using single site-directed mutagenesis showed no evidence for l-lysine binding by isothermal titration calorimetry, which confirmed the predictions. Molecular aspects of the observed ligand specificity are discussed.

Sequences in the ligand-binding domains of the human androgen and progesterone receptors which determine their distinct ligand identities

1997 ◽  
Vol 18 (2) ◽  
pp. 147-160 ◽  
Author(s):  
V Vivat ◽  
D Gofflo ◽  
T Garcia ◽  
J-M Wurtz ◽  
W Bourguet ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Conformational Changes ◽  
Retinoic Acid Receptor ◽  
Three Dimensional ◽  
Progesterone Receptors ◽  
Activation Function ◽  
Binding Domains ◽  
Differential Recognition ◽  
Binding Pockets ◽  
Acetyl Group

ABSTRACT The natural ligands of the progesterone (PR) and androgen (AR) receptors, progesterone and testosterone, differ only by their 17β-substitution. To identify within the AR and PR ligand-binding domains (LBDs) the sequences responsible for the differential recognition of these ligands, chimeric LBDs assembled from five homologous AR/PR 'cassettes' linked to the GAL4-DNA binding domain were constructed, and their ligand binding and transactivation characteristics were determined. Replacing the central cassette 3 of PR by that of AR generated a progesterone- and testosterone-responsive PR LBD with the AR residues 788-RHLS-791 being specifically involved in testosterone recognition, while the introduction of the C-terminal PR cassette 5 into AR conferred progestin responsiveness onto the AR LBD. These results suggest that residues within AR 788-RHLS-791 interact with the testosterone 17β-OH, while PR cassette 5 apparently contains the amino acid(s) specifically involved in the recognition of the progesterone 17β-acetyl group. However, ligand binding and transactivation by these chimeras were significantly decreased compared with those of the parental LBDs, indicating that residues located outside of these cassettes contribute to the proper positioning of the steroids in the AR and PR ligand-binding pockets (LBPs). Indeed, certain AR/PR chimeras acquired efficient ligand binding, but were unable to transactivate, indicating that the ligand was improperly bound in the chimeric LBP and could not induce the conformational changes leading to a transcriptionally competent activation function (AF-2) within the LBD. The properties of the various LBD chimeras are discussed in view of the recently solved three-dimensional structures of the retinoid X receptor α apo- and retinoic acid receptor γ holo-LBDs.

scholarly journals Identification and Characterization of a Novel Class of Extracellular Poly(3-Hydroxybutyrate) Depolymerase from Bacillus sp. Strain NRRL B-14911

2011 ◽  
Vol 77 (22) ◽  
pp. 7924-7932 ◽  
Author(s):  
Wan-Ting Ma ◽  
Ju-Hui Lin ◽  
Hui-Ju Chen ◽  
Syuan-Yi Chen ◽  
Gwo-Chyuan Shaw
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Content Type ◽  
Linker Region ◽  
Phb Depolymerase ◽  
Binding Domains ◽  
Significant Amino Acid Sequence ◽  
Significant Amino Acid

ABSTRACTThe catalytic, linker, and denatured poly(3-hydroxybutyrate) (dPHB)-binding domains of bacterial extracellular PHB depolymerases (PhaZs) are classified into several different types. We now report a novel class of extracellular PHB depolymerase fromBacillussp. strain NRRL B-14911. Its catalytic domain belongs to type 1, whereas its putative linker region neither possesses the sequence features of the three known types of linker domains nor exhibits significant amino acid sequence similarity to them. Instead, this putative linker region can be divided into two distinct linker domains of novel types: LD1 and LD2. LD1 shows significant amino acid sequence similarity to certain regions of a large group of PHB depolymerase-unrelated proteins. LD2 and its homologs are present in a small group of PhaZs. The remaining C-terminal portion of this PhaZ can be further divided into two distinct domains: SBD1 and SBD2. Each domain showed strong binding to dPHB, and there is no significant sequence similarity between them. Each domain neither possesses the sequence features of the two known types of dPHB-binding domains nor shows significant amino acid sequence similarity to them. These unique features indicate the presence of two novel and distinct types of dPHB-binding domains. Homologs of these novel domains also are present in the extracellular PhaZ ofBacillus megateriumand the putative extracellular PhaZs ofBacillus pseudofirmusandBacillussp. strain SG-1. TheBacillussp. NRRL B-14911 PhaZ appears to be a representative of a novel class of extracellular PHB depolymerases.

IDENTIFICATION OF SELETIVE CLAUDIN CATION CHANNEL BLOCKERS

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S25-S26
Author(s):  
Jingjing Ma ◽  
Emma Wu ◽  
Ye Li ◽  
William Seibel ◽  
Le Shen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Homology Model ◽  
Docking Studies ◽  
Channel Blockers ◽  
Binding Modes ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Dynamics Simulations ◽  
In Silico Models

Abstract Compromised epithelial barrier function is known to be associated with inflammatory bowel disease (IBD) and may contribute to disease development. One mechanism of barrier dysfunction is increased expression of paracellular tight junction ion and water channels formed by claudins. Claudin-2 and -15 are two such channels. We hypothesize that blocking these channels could be a viable therapeutic approach to treat diarrhea. In an effort to develop blockers of these channels, we turn to our previously developed and validated in silico models of claudin-15 (Samanta et al. 2018). We reasoned that compounds that can bind with the interior of claudin pores can limit paracellular water and ion flux. Thus, we used docking algorithms to search for putative small molecules that bind in the claudin-15 pore. AutoDock Vina was initially used to assess rigid docking using small compound databases. The small molecules were analyzed based on binding affinity to the pore and visualized using VMD for their potential blockage of the channel. Clusters of binding modes were identified based on the prominent interacting residues of the protein with the small molecules. We initially screened 10,500 compounds from within the UIC Centre for Drug Discovery and a cross-section of 10,000 compounds from the NCI open compound repository. This initial screen allowed us to identify 2 first-in-class selective claudin-15 blockers with efficacy in MDCK monolayers induced to express claudin-15 and in wildtype duodenum. Next, we screened the entire NCI open compound repository for additional molecules structurally related to our best initially identified molecule and this has allowed us to identify 13 additional molecules that increase TER of claudin-15 expressing MDCK monolayers by 90–160%. Additionally, these molecules possess similar structural components that will be collected in a fragment library and explored through molecular dynamics simulations. We also developed a claudin-2 homology model on which we are performing docking studies and in vitro measurements, which we expect will result in similar candidate ligands for blocking claudin-2. Our study will provide important insight into the role of claudin-dependent cation permeability in fundamental physiology, which we believe will lead to the utility of claudin blockers as a novel and much needed approach to treat diseases such as IBD.

scholarly journals Cryptic-site binding mechanism of medium-sized Bcl-xL inhibiting compounds elucidated by McMD-based dynamic docking simulations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gert-Jan Bekker ◽  
Ikuo Fukuda ◽  
Junichi Higo ◽  
Yoshifumi Fukunishi ◽  
Narutoshi Kamiya
Keyword(s):  
Ligand Binding ◽  
Cancer Progression ◽  
Hydrophobic Interactions ◽  
Binding Mechanism ◽  
Docking Simulations ◽  
Large Conformational Change ◽  
Binding Pockets ◽  
Dynamic Docking ◽  
Site Binding ◽  
Apo State

AbstractWe have performed multicanonical molecular dynamics (McMD) based dynamic docking simulations to study and compare the binding mechanism between two medium-sized inhibitors (ABT-737 and WEHI-539) that bind to the cryptic site of Bcl-xL, by exhaustively sampling the conformational and configurational space. Cryptic sites are binding pockets that are transiently formed in the apo state or are induced upon ligand binding. Bcl-xL, a pro-survival protein involved in cancer progression, is known to have a cryptic site, whereby the shape of the pocket depends on which ligand is bound to it. Starting from the apo-structure, we have performed two independent McMD-based dynamic docking simulations for each ligand, and were able to obtain near-native complex structures in both cases. In addition, we have also studied their interactions along their respective binding pathways by using path sampling simulations, which showed that the ligands form stable binding configurations via predominantly hydrophobic interactions. Although the protein started from the apo state, both ligands modulated the pocket in different ways, shifting the conformational preference of the sub-pockets of Bcl-xL. We demonstrate that McMD-based dynamic docking is a powerful tool that can be effectively used to study binding mechanisms involving a cryptic site, where ligand binding requires a large conformational change in the protein to occur.

scholarly journals Paired opposing leukocyte receptors recognizing rapidly evolving ligands are subject to homogenization of their ligand binding domains

2011 ◽  
Vol 63 (12) ◽  
pp. 809-820 ◽  
Author(s):  
Sigbjørn Fossum ◽  
Per Christian Saether ◽  
John Torgils Vaage ◽  
Michael Rory Daws ◽  
Erik Dissen
Keyword(s):  
Ligand Binding ◽  
Binding Domains ◽  
Leukocyte Receptors

Assessing the ligand selectivity of sphingosine kinases using molecular dynamics and MM-PBSA binding free energy calculations

2016 ◽  
Vol 12 (4) ◽  
pp. 1174-1182 ◽  
Author(s):  
Liang Fang ◽  
Xiaojian Wang ◽  
Meiyang Xi ◽  
Tianqi Liu ◽  
Dali Yin
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Model Building ◽  
Binding Free Energy ◽  
Homology Model ◽  
Free Energy Calculations ◽  
Dynamics Simulation ◽  
Ligand Selectivity ◽  
Sphingosine Kinases ◽  
Binding Free Energy Calculations

Three residues of SK1 were identified important for selective SK1 inhibitory activity via SK2 homology model building, molecular dynamics simulation, and MM-PBSA studies.

Docking studies of Nickel-Peptide deformylase (PDF) inhibitors: Exploring the new binding pockets

2006 ◽  
Vol 122 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Qiang Wang ◽  
Datong Zhang ◽  
Jianwu Wang ◽  
Zhengting Cai ◽  
Weiren Xu
Keyword(s):  
Docking Studies ◽  
Peptide Deformylase ◽  
Binding Pockets

scholarly journals Biochemical and NMR Mapping of the Interface between CREB-binding Protein and Ligand Binding Domains of Nuclear Receptor

2004 ◽  
Vol 280 (7) ◽  
pp. 5682-5692 ◽  
Author(s):  
Fabrice A. C. Klein ◽  
R. Andrew Atkinson ◽  
Noelle Potier ◽  
Dino Moras ◽  
Jean Cavarelli
Keyword(s):  
Ligand Binding ◽  
Nuclear Receptor ◽  
Binding Protein ◽  
Creb Binding Protein ◽  
Binding Domains

Molecular characterization of a novel mycovirus isolated from Rhizoctonia solani AG-1 IA 9-11

2021 ◽  
Author(s):  
Yang Sun ◽  
Yan qiong Li ◽  
Wen han Dong ◽  
Ai li Sun ◽  
Ning wei Chen ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Rna Virus ◽  
Dsrna Virus ◽  
Open Reading Frames ◽  
The Family ◽  
Significant Amino Acid Sequence ◽  
Overlapping Open Reading Frames ◽  
Significant Amino Acid ◽  
Reading Frames

Abstract The complete genome of the dsRNA virus isolated from Rhizoctonia solani AG-1 IA 9–11 (designated as Rhizoctonia solani dsRNA virus 11, RsRV11 ) were determined. The RsRV11 genome was 9,555 bp in length, contained three conserved domains, SMC, PRK and RT-like super family, and encoded two non-overlapping open reading frames (ORFs). ORF1 potentially coded for a 204.12 kDa predicted protein, which shared low but significant amino acid sequence identities with the putative protein encoded by Rhizoctonia solani RNA virus HN008 (RsRV-HN008) ORF1. ORF2 potentially coded for a 132.41 kDa protein which contained the conserved motifs of the RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis indicated that RsRV11 was clustered with RsRV-HN008 in a separate clade independent of other virus families. It implies that RsRV11, along with RsRV-HN008 possibly a new fungal virus taxa closed to the family Megabirnaviridae, and RsRV11 is a new member of mycoviruses.

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