Non Ribosomal Peptides : A monomeric puzzle

National audienceNonribosomal peptides (NRPs) are increasingly studied because they harbor activities which can be exploited in various domains. They are often denoted as graphs illustrating their chemical structure, where the atoms are represented by nodes and the chemical bonds by arcs. Another possible representation is the monomeric structure. This structure, inspired by the biosynthetic pathway of these peptides, is effectuated by large enzymatic complexes which assemble together smaller compounds called monomers. Consequently, the nonribosomal peptides are composed of a great variety of monomers (more than 500 are known) including amino acids, lipids and carbohydrates. Likewise, nonpetidic bonds are formed between multiple monomers, producing peptides with cycles and/or branches. Thus, the monomeric structure is a graph formed by the monomers present in the peptide and their interlinking chemical bonds. Until now, there did not exist a tool allowing for the conversion between the atomic and monomeric structures. This article presents a novel algorithm capable of localising the monomers from a reference list in the chemical structures of peptides extracted from the Norine database. The algorithm is based on a heuristic that utilizes chemical information of NRPs. The preliminary results are encouraging, and should lead to further studies.Les peptides non-ribosomiques (NRP) sont des molécules de plus en plus étudiées car elles présentent des activités ayant des applications principalement dans le domaine pharmaceutique. Elles sont souvent décrites par leur structure chimique, c'est-a-dire un graphe dont les noeuds sont des atomes et les arêtes les liaisons chimiques. Une autre représentation possible est la structure monomérique. Cette structure, inspirée de la voie de synthèse de ces peptides, est réalisé par de gros complexes enzymatiques qui assemblent les briques de base, appelées monomères. Ainsi, les peptides non-ribosomiques sont composés d'une grande variété de monomères (plus de 500 recensés jusqu'à présent) tels que des acides aminés, mais aussi des lipides ou des sucres. De plus, des liaisons non-peptidiques peuvent être formées entre certains monomères, ce qui produit des peptides contenant des cycles et/ou des branchements. La structure monomérique est donc le graphe formé par les monomères présents dans le peptide et les liaisons qui les relient. A l'heure actuelle, il n'existe pas d'outil permettant de convertir la structure chimique d'un peptide non-ribosomique en sa structure monomérique. Cet article présente un algorithme capable de localiser les monomères d'une liste de référence dans les structures chimiques des peptides de la base de données Norine. Il est basé sur une heuristique gloutonne qui utilise des connaissances sur la chimie des NRP. Les résultats préliminaires sont satisfaisants et devraient conduire à de nouvelles études

Structural pattern matching of nonribosomal peptides

<p>Abstract</p> <p>Background</p> <p>Nonribosomal peptides (NRPs), bioactive secondary metabolites produced by many microorganisms, show a broad range of important biological activities (e.g. antibiotics, immunosuppressants, antitumor agents). NRPs are mainly composed of amino acids but their primary structure is not always linear and can contain cycles or branchings. Furthermore, there are several hundred different monomers that can be incorporated into NRPs. The N<smcaps>ORINE</smcaps> database, the first resource entirely dedicated to NRPs, currently stores more than 700 NRPs annotated with their monomeric peptide structure encoded by undirected labeled graphs. This opens a way to a systematic analysis of structural patterns occurring in NRPs. Such studies can investigate the functional role of some monomeric chains, or analyse NRPs that have been computationally predicted from the synthetase protein sequence. A basic operation in such analyses is the search for a given structural pattern in the database.</p> <p>Results</p> <p>We developed an efficient method that allows for a quick search for a structural pattern in the N<smcaps>ORINE</smcaps> database. The method identifies all peptides containing a pattern substructure of a given size. This amounts to solving a variant of the maximum common subgraph problem on pattern and peptide graphs, which is done by computing cliques in an appropriate compatibility graph.</p> <p>Conclusion</p> <p>The method has been incorporated into the N<smcaps>ORINE</smcaps> database, available at <url>http://bioinfo.lifl.fr/norine</url>. Less than one second is needed to search for a pattern in the entire database.</p

NRPS toolbox for the discovery of new nonribosomal peptides and synthetases

National audienceNonribosomal peptide synthetases are huge multi-enzymatic complexes synthesizing peptides, but not through the classical process of transcription and then translation. The synthetases are organised in modules, each one integrating an amino acid in the final peptide. The modules are divided in domains providing specialized activities. So, those enzymes are as diverse as their products. We present our toolbox designed to annotate them accurately and promising results obtained on some Burkholderia, Bacillus and Pseudomonas genomes

NORINE: a database of nonribosomal peptides

Norine is the first database entirely dedicated to nonribosomal peptides (NRPs). In bacteria and fungi, in addition to the traditional ribosomal proteic biosynthesis, an alternative ribosome-independent pathway called NRP synthesis allows peptide production. It is performed by huge protein complexes called nonribosomal peptide synthetases (NRPSs). The molecules synthesized by NRPS contain a high proportion of nonproteogenic amino acids. The primary structure of these peptides is not always linear but often more complex and may contain cycles and branchings. In recent years, NRPs attracted a lot of attention because of their biological activities and pharmacological properties (antibiotic, immunosuppressor, antitumor, etc.). However, few computational resources and tools dedicated to those peptides have been available so far. Norine is focused on NRPs and contains more than 700 entries. The database is freely accessible at http://bioinfo.lifl.fr/norine/. It provides a complete computational tool for systematic study of NRPs in numerous species, and as such, should permit to obtain a better knowledge of these metabolic products and underlying biological mechanisms, and ultimately to contribute to the redesigning of natural products in order to obtain new bioactive compounds for drug discovery

Data updates on Norine, the reference Non-Ribosomal Peptide knowledge base

International audienc

Non Ribosomal Peptides : A monomeric puzzle

National audienceNonribosomal peptides (NRPs) are increasingly studied because they harbor activities which can be exploited in various domains. They are often denoted as graphs illustrating their chemical structure, where the atoms are represented by nodes and the chemical bonds by arcs. Another possible representation is the monomeric structure. This structure, inspired by the biosynthetic pathway of these peptides, is effectuated by large enzymatic complexes which assemble together smaller compounds called monomers. Consequently, the nonribosomal peptides are composed of a great variety of monomers (more than 500 are known) including amino acids, lipids and carbohydrates. Likewise, nonpetidic bonds are formed between multiple monomers, producing peptides with cycles and/or branches. Thus, the monomeric structure is a graph formed by the monomers present in the peptide and their interlinking chemical bonds. Until now, there did not exist a tool allowing for the conversion between the atomic and monomeric structures. This article presents a novel algorithm capable of localising the monomers from a reference list in the chemical structures of peptides extracted from the Norine database. The algorithm is based on a heuristic that utilizes chemical information of NRPs. The preliminary results are encouraging, and should lead to further studies.Les peptides non-ribosomiques (NRP) sont des molécules de plus en plus étudiées car elles présentent des activités ayant des applications principalement dans le domaine pharmaceutique. Elles sont souvent décrites par leur structure chimique, c'est-a-dire un graphe dont les noeuds sont des atomes et les arêtes les liaisons chimiques. Une autre représentation possible est la structure monomérique. Cette structure, inspirée de la voie de synthèse de ces peptides, est réalisé par de gros complexes enzymatiques qui assemblent les briques de base, appelées monomères. Ainsi, les peptides non-ribosomiques sont composés d'une grande variété de monomères (plus de 500 recensés jusqu'à présent) tels que des acides aminés, mais aussi des lipides ou des sucres. De plus, des liaisons non-peptidiques peuvent être formées entre certains monomères, ce qui produit des peptides contenant des cycles et/ou des branchements. La structure monomérique est donc le graphe formé par les monomères présents dans le peptide et les liaisons qui les relient. A l'heure actuelle, il n'existe pas d'outil permettant de convertir la structure chimique d'un peptide non-ribosomique en sa structure monomérique. Cet article présente un algorithme capable de localiser les monomères d'une liste de référence dans les structures chimiques des peptides de la base de données Norine. Il est basé sur une heuristique gloutonne qui utilise des connaissances sur la chimie des NRP. Les résultats préliminaires sont satisfaisants et devraient conduire à de nouvelles études

Norine: a powerful resource for novel nonribosomal peptide discovery

International audienceSince its first release in 2008, Norine remains the unique resource completely devoted to nonribosomal peptides (NRPs). They are very attractive microbial secondary metabolites, displaying a remarkable diversity of structure and functions. Norine (http://bioinfo.lifl.fr/NRP) includes a database now containing more than 1160 annotated peptides and user-friendly interfaces enabling the querying of the database, through the annotations or the structure of the peptides. Dedicated tools are associated for structural comparison of the compounds and prediction of their biological activities. In this paper, we start by describing the knowledgebase and the dedicated tools. We then present some user cases to show how useful Norine is for the discovery of novel nonribosomal peptides

Norine, Florine, s2m : powerful bioinformatics resource and tools for the discovery of novel nonribosomal peptides, natural metabolites with versatile activities

International audienceNonRibosomal peptides (NRPs) are a huge untapped resource of natural products displaying activities with applications in health (i.e. antibiotics) or in biocontrol (especially siderophores and lipopeptides with antifungal activity). NRPs are microbial secondary metabolites produced by enzymatic complexes, so-called non-ribosomal peptide synthetases (NRPSs). These modular assembly lines work step by step to build the peptides, each module adding one monomer to the peptidic chain. Considering the modular organization of NRPSs, and the structural specific features of the NRPs, dedicated bioinformatics tools have been developed with the aim of accelerating the screening for new active metabolites

Paraburkholderia phytofirmans PsJN-Plants Interaction: From Perception to the Induced Mechanisms

The use of plant-associated bacteria has received many scientific and economic attention as an effective and alternative method to reduce the chemical pesticides use in agriculture. The genus Burkholderia includes at least 90 species including pathogenic strains, plant pathogens, as well as plant beneficial species as those related to Paraburkholderia, which has been reported to be associated with plants and exerts a positive effect on plant growth and fitness. Paraburkholderia phytofirmans PsJN, a beneficial endophyte able to colonize a wide range of plants, is an established model for plant-associated endophytic bacteria. Indeed, in addition to its plant growth promoting ability, it can also induce plant resistance against biotic as well as abiotic stresses. Here, we summarized an inventory of knowledge on PsJN-plant interaction, from the perception to the resistance mechanisms induced in the plant by a way of the atypical colonization mode of this endophyte. We also have carried out an extensive genome analysis to identify all gene clusters which contribute to the adaptive mechanisms under different environments and partly explaining the high ecological competence of P. phytofirmans PsJN