Etude moléculaire et structurale d'une intégrase rétrovirale pour le développement de nouveaux antirétroviraux et étude cristallographique d' -galactosidases thermostables issues du microorganisme Geobacillus stearothermophilus

Integrase (IN) is a key protein in the retrovirus life cycle and constitutes an important therapeutic target for the development of antiretroviral compounds. This enzyme is involved in the early phase of theretroviral replication cycle and catalyses the retrotranscribed viral DNA integration into the host cell genome.The teams of BioCrystallography and Retrovirology of Lyon Gerland demonstrated by X ray crystallography, the existence of a new dimeric assembly of the central catalytic domain (CCD) of Rous Associated Virus type 1integrase or RAV 1 IN. As part of my thesis work, a protocol of overproduction and purification of the H103Cisolated catalytic domain mutant was developed to demonstrate the existence of this dimeric assembly insolution stabilized by an inter molecular disulfide bond. Biochemical and biophysical methods were developed to test the ability of small molecules of interest to bind and stabilize this "new" assembly. A protocol ofoverproduction and purification of full length RAV1 integrase was developed. Crystallization trials and SAXSstudies were undertaken. The H103C mutant of the entire protein was produced to verify the formation of the"new" interface on the full length protein.The microorganism Geobacillus stearothermophilus produces two thermostable ɑ-galactosidases named AgaA and AgaB, which belong to theGH36 glycoside hydrolase family. These two isoenzymes share97% sequence identity, but have different catalytic properties. A collaborative study was initiated with theInstitute of Industrial Genetics, University of Stuttgart (Germany),to better understand the catalytic specificity of these two isoenzymes. The crystal structures of AgaA and AgaB were solved in two different crystal systems.The crystal structure of the mutant AgaA A355E, which has catalytic properties similar of those of AgaB, wasalso determined. These three structures show that the A355E substitution results in a signifiant displacement of the W336 tryptophan residue from the catalytic subsite -1. This could explain the catalytic specificities of the two isoenzymesL'intégrase (IN) est une protéine clé du cycle de réplication des rétrovirus et constitue une cible thérapeutique importante. Nous avons découvert par cristallographie aux rayons X, une nouvelle possibilité d'assemblage dimérique du domaine central catalytique de l'intégrase du Rous associated virus type I (RAV-1 IN). Dans le cadre de mon travail de thèse, un protocole de surproduction et de purification d'un mutant du domaine catalytique isolé (H103C) a été optimisé, afin de démontrer l'existence de cet assemblage en solution grâce à un pont disulfure inter-moléculaire. Différentes méthodes ont été mises au point, afin de tester la ca pacité de petites molécules d'intérêt à se lier et à stabiliser ce "nouvel" assemblage. Un protocole de surproduction et de purification de l'IN entière du RAV-1 a également été développé et mis au point. Des études structurales ont été réalisées. Un mutant H103C de la protéine entière a été produit, afin de vérifier la formation de la "nouvelle" interface sur la protéine entière. Le microorganisme Geobacillus stearothermophilus produit deux ɑ-galactosidases, AgaA et AgaB, qui appartiennent à la famille GH36 des glycosides hydrolases. Ces deux isoenzymes partagent 97 % d'identité de séquence, mais ont des activités catalytiques différentes. Les structures cristallines d'AgaA et AgaB ont été résolues ainsi que la structures du mutant AgaA et AgaB ont été résolues ainsi que la structure du mutant AgaA A355E, qui présente des caractéristiques enzymatiques similaires de AgaB. L'analyse de ces trois structures montre que la substitution A355E entraîne un déplacement significatif du tryptophane du sous-site catalytiques -1. Ce mouvement peut expliquer les spécificités catalytiques des deux isoenzymes

Molecular architecture of the endocytic TPLATE complex

Eukaryotic cells rely on endocytosis to regulate their plasma membrane proteome and lipidome. Most eukaryotic groups, except fungi and animals, have retained the evolutionary ancient TSET complex as an endocytic regulator. Unlike other coatomer complexes, structural insight into TSET is lacking. Here, we reveal the molecular architecture of plant TSET [TPLATE complex (TPC)] using an integrative structural approach. We identify crucial roles for specific TSET subunits in complex assembly and membrane interaction. Our data therefore generate fresh insight into the differences between the hexameric TSET in Dictyostelium and the octameric TPC in plants. Structural elucidation of this ancient adaptor complex represents the missing piece in the coatomer puzzle and vastly advances our functional as well as evolutionary insight into the process of endocytosis

Distinct EH domains of the endocytic TPLATE complex confer lipid and protein binding

Clathrin-mediated endocytosis (CME) is the gatekeeper of the plasma membrane. In contrast to animals and yeasts, CME in plants depends on the TPLATE complex (TPC), an evolutionary ancient adaptor complex. However, the mechanistic contribution of the individual TPC subunits to plant CME remains elusive. In this study, we used a multidisciplinary approach to elucidate the structural and functional roles of the evolutionary conserved N-terminal Eps15 homology (EH) domains of the TPC subunit AtEH1/Pan1. By integrating high-resolution structural information obtained by X-ray crystallography and NMR spectroscopy with all-atom molecular dynamics simulations, we provide structural insight into the function of both EH domains. Both domains bind phosphatidic acid with a different strength, and only the second domain binds phosphatidylinositol 4,5-bisphosphate. Unbiased peptidome profiling by mass-spectrometry revealed that the first EH domain preferentially interacts with the double N-terminal NPF motif of a previously unidentified TPC interactor, the integral membrane protein Secretory Carrier Membrane Protein 5 (SCAMP5). Furthermore, we show that AtEH/Pan1 proteins control the internalization of SCAMP5 via this double NPF peptide interaction motif. Collectively, our structural and functional studies reveal distinct but complementary roles of the EH domains of AtEH/Pan1 in plant CME and connect the internalization of SCAMP5 to the TPLATE complex. AtEH/Pan1 proteins contain two N-terminal Eps15 homology (EH) domains and are subunits of the endocytic TPLATE complex present in plants. Here, the authors combine X-ray crystallography, NMR and MD simulations with biochemical and in planta analysis to characterize the two AtEH1/Pan1 EH domains and reveal their structural differences and complementary functional roles

Etude moléculaire et structurale d'une intégrase rétrovirale pour le développement de nouveaux antirétroviraux et étude cristallographique d' -galactosidases thermostables issues du microorganisme <em>Geobacillus stearothermophilus </em>

Integrase (IN) is a key protein in the retrovirus life cycle and constitutes an important therapeutic target for the development of antiretroviral compounds. This enzyme is involved in the early phase of theretroviral replication cycle and catalyses the retrotranscribed viral DNA integration into the host cell genome.The teams of BioCrystallography and Retrovirology of Lyon Gerland demonstrated by X ray crystallography, the existence of a new dimeric assembly of the central catalytic domain (CCD) of Rous Associated Virus type 1integrase or RAV 1 IN. As part of my thesis work, a protocol of overproduction and purification of the H103Cisolated catalytic domain mutant was developed to demonstrate the existence of this dimeric assembly insolution stabilized by an inter molecular disulfide bond. Biochemical and biophysical methods were developed to test the ability of small molecules of interest to bind and stabilize this "new" assembly. A protocol ofoverproduction and purification of full length RAV1 integrase was developed. Crystallization trials and SAXSstudies were undertaken. The H103C mutant of the entire protein was produced to verify the formation of the"new" interface on the full length protein.The microorganism Geobacillus stearothermophilus produces two thermostable ɑ-galactosidases named AgaA and AgaB, which belong to theGH36 glycoside hydrolase family. These two isoenzymes share97% sequence identity, but have different catalytic properties. A collaborative study was initiated with theInstitute of Industrial Genetics, University of Stuttgart (Germany),to better understand the catalytic specificity of these two isoenzymes. The crystal structures of AgaA and AgaB were solved in two different crystal systems.The crystal structure of the mutant AgaA A355E, which has catalytic properties similar of those of AgaB, wasalso determined. These three structures show that the A355E substitution results in a signifiant displacement of the W336 tryptophan residue from the catalytic subsite -1. This could explain the catalytic specificities of the two isoenzymesL'intégrase (IN) est une protéine clé du cycle de réplication des rétrovirus et constitue une cible thérapeutique importante. Nous avons découvert par cristallographie aux rayons X, une nouvelle possibilité d'assemblage dimérique du domaine central catalytique de l'intégrase du Rous associated virus type I (RAV-1 IN). Dans le cadre de mon travail de thèse, un protocole de surproduction et de purification d'un mutant du domaine catalytique isolé (H103C) a été optimisé, afin de démontrer l'existence de cet assemblage en solution grâce à un pont disulfure inter-moléculaire. Différentes méthodes ont été mises au point, afin de tester la ca pacité de petites molécules d'intérêt à se lier et à stabiliser ce "nouvel" assemblage. Un protocole de surproduction et de purification de l'IN entière du RAV-1 a également été développé et mis au point. Des études structurales ont été réalisées. Un mutant H103C de la protéine entière a été produit, afin de vérifier la formation de la "nouvelle" interface sur la protéine entière. Le microorganisme Geobacillus stearothermophilus produit deux ɑ-galactosidases, AgaA et AgaB, qui appartiennent à la famille GH36 des glycosides hydrolases. Ces deux isoenzymes partagent 97 % d'identité de séquence, mais ont des activités catalytiques différentes. Les structures cristallines d'AgaA et AgaB ont été résolues ainsi que la structures du mutant AgaA et AgaB ont été résolues ainsi que la structure du mutant AgaA A355E, qui présente des caractéristiques enzymatiques similaires de AgaB. L'analyse de ces trois structures montre que la substitution A355E entraîne un déplacement significatif du tryptophane du sous-site catalytiques -1. Ce mouvement peut expliquer les spécificités catalytiques des deux isoenzymes

Molecular and structural study of a retroviral integrase for the developemnt of new antiretroviral compounds and structural study of thermostable ɑ-galactosidases from Geobacillus stearothermophilus microorganism

L'intégrase (IN) est une protéine clé du cycle de réplication des rétrovirus et constitue une cible thérapeutique importante. Nous avons découvert par cristallographie aux rayons X, une nouvelle possibilité d'assemblage dimérique du domaine central catalytique de l'intégrase du Rous associated virus type I (RAV-1 IN). Dans le cadre de mon travail de thèse, un protocole de surproduction et de purification d'un mutant du domaine catalytique isolé (H103C) a été optimisé, afin de démontrer l'existence de cet assemblage en solution grâce à un pont disulfure inter-moléculaire. Différentes méthodes ont été mises au point, afin de tester la ca pacité de petites molécules d'intérêt à se lier et à stabiliser ce "nouvel" assemblage. Un protocole de surproduction et de purification de l'IN entière du RAV-1 a également été développé et mis au point. Des études structurales ont été réalisées. Un mutant H103C de la protéine entière a été produit, afin de vérifier la formation de la "nouvelle" interface sur la protéine entière. Le microorganisme Geobacillus stearothermophilus produit deux ɑ-galactosidases, AgaA et AgaB, qui appartiennent à la famille GH36 des glycosides hydrolases. Ces deux isoenzymes partagent 97 % d'identité de séquence, mais ont des activités catalytiques différentes. Les structures cristallines d'AgaA et AgaB ont été résolues ainsi que la structures du mutant AgaA et AgaB ont été résolues ainsi que la structure du mutant AgaA A355E, qui présente des caractéristiques enzymatiques similaires de AgaB. L'analyse de ces trois structures montre que la substitution A355E entraîne un déplacement significatif du tryptophane du sous-site catalytiques -1. Ce mouvement peut expliquer les spécificités catalytiques des deux isoenzymes.Integrase (IN) is a key protein in the retrovirus life cycle and constitutes an important therapeutic target for the development of antiretroviral compounds. This enzyme is involved in the early phase of theretroviral replication cycle and catalyses the retrotranscribed viral DNA integration into the host cell genome.The teams of BioCrystallography and Retrovirology of Lyon Gerland demonstrated by X ray crystallography, the existence of a new dimeric assembly of the central catalytic domain (CCD) of Rous Associated Virus type 1integrase or RAV 1 IN. As part of my thesis work, a protocol of overproduction and purification of the H103Cisolated catalytic domain mutant was developed to demonstrate the existence of this dimeric assembly insolution stabilized by an inter molecular disulfide bond. Biochemical and biophysical methods were developed to test the ability of small molecules of interest to bind and stabilize this "new" assembly. A protocol ofoverproduction and purification of full length RAV1 integrase was developed. Crystallization trials and SAXSstudies were undertaken. The H103C mutant of the entire protein was produced to verify the formation of the"new" interface on the full length protein.The microorganism Geobacillus stearothermophilus produces two thermostable ɑ-galactosidases named AgaA and AgaB, which belong to theGH36 glycoside hydrolase family. These two isoenzymes share97% sequence identity, but have different catalytic properties. A collaborative study was initiated with theInstitute of Industrial Genetics, University of Stuttgart (Germany),to better understand the catalytic specificity of these two isoenzymes. The crystal structures of AgaA and AgaB were solved in two different crystal systems.The crystal structure of the mutant AgaA A355E, which has catalytic properties similar of those of AgaB, wasalso determined. These three structures show that the A355E substitution results in a signifiant displacement of the W336 tryptophan residue from the catalytic subsite -1. This could explain the catalytic specificities of the two isoenzyme

A crystal structure of the catalytic core domain of an avian sarcoma and leukemia virus integrase suggests an alternate dimeric assembly

Integrase (IN) is an important therapeutic target in the search for anti-Human Immunodeficiency Virus (HIV) inhibitors. This enzyme is composed of three domains and is hard to crystallize in its full form. First structural results on IN were obtained on the catalytic core domain (CCD) of the avian Rous and Sarcoma Virus strain Schmidt-Ruppin A (RSV-A) and on the CCD of HIV-1 IN. A ribonuclease-H like motif was revealed as well as a dimeric interface stabilized by two pairs of alpha-helices (alpha1/alpha5, alpha5/alpha1). These structural features have been validated in other structures of IN CCDs. We have determined the crystal structure of the Rous-associated virus type-1 (RAV-1) IN CCD to 1.8 A resolution. RAV-1 IN shows a standard activity for integration and its CCD differs in sequence from that of RSV-A by a single accessible residue in position 182 (substitution A182T). Surprisingly, the CCD of RAV-1 IN associates itself with an unexpected dimeric interface characterized by three pairs of alpha-helices (alpha3/alpha5, alpha1/alpha1, alpha5/alpha3). A182 is not involved in this novel interface, which results from a rigid body rearrangement of the protein at its alpha1, alpha3, alpha5 surface. A new basic groove that is suitable for single-stranded nucleic acid binding is observed at the surface of the dimer. We have subsequently determined the structure of the mutant A182T of RAV-1 IN CCD and obtained a RSV-A IN CCD-like structure with two pairs of buried alpha-helices at the interface. Our results suggest that the CCD of avian INs can dimerize in more than one state. Such flexibility can further explain the multifunctionality of retroviral INs, which beside integration of dsDNA are implicated in different steps of the retroviral cycle in presence of viral ssRNA

The design and synthesis of inhibitors of Mycobacterium tuberculosis thymidylate kinase (MtTMPK)

Thymidylate kinase (TMPK) phosphorylates thymidine 5’-monophosphate (dTMP) to thymidine 5’-diphosphate (dTDP) and has been proposed as an attractive anti-tubercular target. By mimicking the structure of the substrate (dTMP), we have previously discovered different series of nucleoside analogues with Mycobacterium tuberculosis (Mt) TMPK inhibitory activities in the micromolar range. Based on recently reported potent piperidin-3-yl-thymine inhibitors of Gram-positive bacterial TMPK, we report a series of isomeric N-benzyl-substituted piperidin-4-yl-thymine analogues, some of which demonstrate very promising MtTMPK inhibitory potency. This poster will discuss the synthesis, MtTMPK inhibitory activity, as well as structural data on how these new inhibitors interact with the target enzyme

A crystal structure of the catalytic core domain of an avian sarcoma and leukemia virus integrase suggests an alternate dimeric assembly.

Integrase (IN) is an important therapeutic target in the search for anti-Human Immunodeficiency Virus (HIV) inhibitors. This enzyme is composed of three domains and is hard to crystallize in its full form. First structural results on IN were obtained on the catalytic core domain (CCD) of the avian Rous and Sarcoma Virus strain Schmidt-Ruppin A (RSV-A) and on the CCD of HIV-1 IN. A ribonuclease-H like motif was revealed as well as a dimeric interface stabilized by two pairs of α-helices (α1/α5, α5/α1). These structural features have been validated in other structures of IN CCDs. We have determined the crystal structure of the Rous-associated virus type-1 (RAV-1) IN CCD to 1.8 Å resolution. RAV-1 IN shows a standard activity for integration and its CCD differs in sequence from that of RSV-A by a single accessible residue in position 182 (substitution A182T). Surprisingly, the CCD of RAV-1 IN associates itself with an unexpected dimeric interface characterized by three pairs of α-helices (α3/α5, α1/α1, α5/α3). A182 is not involved in this novel interface, which results from a rigid body rearrangement of the protein at its α1, α3, α5 surface. A new basic groove that is suitable for single-stranded nucleic acid binding is observed at the surface of the dimer. We have subsequently determined the structure of the mutant A182T of RAV-1 IN CCD and obtained a RSV-A IN CCD-like structure with two pairs of buried α-helices at the interface. Our results suggest that the CCD of avian INs can dimerize in more than one state. Such flexibility can further explain the multifunctionality of retroviral INs, which beside integration of dsDNA are implicated in different steps of the retroviral cycle in presence of viral ssRNA

Synthesis, Crystal Structure, Inhibitory Activity and Molecular Docking of Coumarins/Sulfonamides Containing Triazolyl Pyridine Moiety as Potent Selective Carbonic Anhydrase IX and XII Inhibitors

International audienceIn this work, two classes of Carbonic Anhydrase (CA) inhibitors, sulfonamide and coumarin derivatives linked to pyta moiety (2a-b) and their corresponding rhenium complexes (3a-b), were designed. These compounds were synthesized and fully characterized by classical analytical methods and X-ray diffraction. All the synthesized compounds were evaluated for their inhibitory activity against the hCA isoforms I, II, IX and XII. They exhibited high inhibitory activities in the range of nanomolar for both hCA IX and hCA XII isoforms. The sulfonamide compound 2a showed the strongest inhibition against the tumour-associated hCA IX isoform with a Ki of 11.7 nM. The tumour-associated isoforms hCA IX and hCA XII were selectively inhibited by all the coumarin derivatives, with inhibition constants ranging from 12.7 nM (2b) to 44.5 nM (3b), while the hCA I and II isoforms were slightly inhibited (in the micromolar range), as expected. In terms of selectivity, compared to previously published rhenium complex-based CA inhibitors, complex 3b showed one of the highest selectivities against hCA IX and hCA XII compared to the off-target isoforms hCA I and hCA II, making it a potential anti-cancer drug candidate. Molecular docking calculations were performed to investigate the inhibition profiles of the investigated compounds at the tumour-associated hCA IX active site and to rationalize our results

Structure Guided Lead Generation toward Nonchiral M. tuberculosis Thymidylate Kinase Inhibitors

International audienceIn recent years, thymidylate kinase (TMPK), an enzyme indispensable for bacterial DNA biosynthesis, has been pursued for the development of new antibacterial agents including against Mycobacterium tuberculosis, the causative agent for the widespread infectious disease tuberculosis (TB). In response to a growing need for more effective anti-TB drugs, we have built upon our previous efforts toward the exploration of novel and potent Mycobacterium tuberculosis TMPK ( MtTMPK) inhibitors, and reported here the design of a novel series of non-nucleoside inhibitors of MtTMPK. The inhibitors display hitherto unexplored interactions in the active site of MtTMPK, offering new insights into structure-activity relationships. To investigate the discrepancy between enzyme inhibitory activity and the whole-cell activity, experiments with efflux pump inhibitors and efflux pump knockout mutants were performed. The minimum inhibitory concentrations of particular inhibitors increased significantly when determined for the efflux pump mmr knockout mutant, which partly explains the observed dissonanc