MOTIVATION: Studying the genetic makeup of viruses and phages through genome analysis is crucial for comprehending their function in causing diseases, progressing medicine, tracing their evolutionary history, monitoring the environment, and creating innovative biotechnologies. However, accessing the necessary data can be challenging due to a lack of dedicated comparative genomic tools and viral and phage databases, which are often outdated. Moreover, many wet bench experimentalists may not have the computational proficiency required to manipulate large amounts of genomic data. RESULTS: We have developed VAPEX (Virus And Phage EXplorer), a web server which is supported by a database and features a user-friendly web interface. This tool enables users to easily perform various genomic analysis queries on all natural viruses and phages that have been fully sequenced and are listed in the NCBI compendium. VAPEX therefore excels in producing visual depictions of fully resolved synteny maps, which is one of its key strengths. VAPEX has the ability to exhibit a vast array of orthologous gene classes simultaneously through the use of symbolic representation. Additionally, VAPEX can fully analyze user-submitted viral and phage genomes, including those that have not yet been annotated. AVAILABILITY AND IMPLEMENTATION: VAPEX can be accessed from all current web browsers such as Chrome, Firefox, Edge, Safari, and Opera. VAPEX is freely accessible at https://archaea.i2bc.paris-saclay.fr/vapex/.

MOTIVATION: The retrieval of a single gene sequence and context from completely sequenced bacterial and archaeal genomes constitutes an intimidating task for the wet bench biologist. Existing web-based genome browsers are either too complex for routine use or only provide a subset of the available prokaryotic genomes. RESULTS: We have developed BAGET 2.0 (Bacterial and Archaeal Gene Exploration Tool), an updated web service granting access in just three mouse clicks to the sequence and synteny of any gene from completely sequenced bacteria and archaea. User-provided annotated genomes can be processed as well. BAGET 2.0 relies on a local database updated on a daily basis. AVAILABILITY AND IMPLEMENTATION: BAGET 2.0 befits all current browsers such as Chrome, Firefox, Edge, Opera and Safari. Internet Explorer 11 is supported. BAGET 2.0 is freely accessible at https://archaea.i2bc.paris-saclay.fr/baget/.

MOTIVATION: Comparative plasmid genome analyses require complex tools, the manipulation of large numbers of sequences and constitute a daunting task for the wet bench experimentalist. Dedicated plasmid databases are sparse, only comprise bacterial plasmids and provide exclusively access to sequence similarity searches. RESULTS: We have developed Web-Assisted Symbolic Plasmid Synteny (WASPS), a web service granting protein and DNA sequence similarity searches against a database comprising all completely sequenced natural plasmids from bacterial, archaeal and eukaryal origin. This database pre-calculates orthologous protein clustering and enables WASPS to generate fully resolved plasmid synteny maps in real time using internal and user-provided DNA sequences. AVAILABILITY AND IMPLEMENTATION: WASPS queries befit all current browsers such as Firefox, Edge or Safari while the best functionality is achieved with Chrome. Internet Explorer is not supported. WASPS is freely accessible at https://archaea.i2bc.paris-saclay.fr/wasps/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

BACKGROUND: The study of the conservation of gene order or synteny constitutes a powerful methodology to assess the orthology of genomic regions and to predict functional relationships between genes. The exponential growth of microbial genomic databases is expected to improve synteny predictions significantly. Paradoxically, this genomic data plethora, without information on organisms relatedness, could impair the performance of synteny analysis programs. RESULTS: In this work, I present SyntTax, a synteny web service designed to take full advantage of the large amount or archaeal and bacterial genomes by linking them through taxonomic relationships. SyntTax incorporates a full hierarchical taxonomic tree allowing intuitive access to all completely sequenced prokaryotes. Single or multiple organisms can be chosen on the basis of their lineage by selecting the corresponding rank nodes in the tree. The synteny methodology is built upon our previously described Absynte algorithm with several additional improvements. CONCLUSIONS: SyntTax aims to produce robust syntenies by providing prompt access to the taxonomic relationships connecting all completely sequenced microbial genomes. The reduction in redundancy offered by lineage selection presents the benefit of increasing accuracy while reducing computation time. This web tool was used to resolve successfully several conserved complex gene clusters described in the literature. In addition, particular features of SyntTax permit the confirmation of the involvement of the four components constituting the E. coli YgjD multiprotein complex responsible for tRNA modification. By analyzing the clustering evolution of alternative gene fusions, new proteins potentially interacting with this complex could be proposed. The web service is available at http://archaea.u-psud.fr/SyntTax.

SUMMARY: Absynte (Archaeal and Bacterial Synteny Explorer) is a web-based service designed to display local syntenies in completely sequenced prokaryotic chromosomes. The genomic contexts are determined with a multiple center star clustering topology on the basis of a user-provided protein sequence and all (or a set of) chromosomes from the publicly available archaeal and bacterial genomes. The results consist in a dynamic web page where a consistent color-coding permits a rapid visual evaluation of the relative positioning of genes with similar sequences within the synteny. Each gene composing the synteny can be further queried interactively using either local or remote databases. Absynte results can be exported in .CSV or high-resolution, .PDF formats for printing, archival, further editing or publication purposes. Performance, real-time computation, user-friendliness and daily database updates constitute the principal advantages of Absynte over similar web services. AVAILABILITY: http://archaea.u-psud.fr/absynte CONTACT: [email protected].

BACKGROUND: The binding of regulatory proteins to their specific DNA targets determines the accurate expression of the neighboring genes. The in silico prediction of new binding sites in completely sequenced genomes is a key aspect in the deeper understanding of gene regulatory networks. Several algorithms have been described to discriminate against false-positives in the prediction of new binding targets; however none of them has been implemented so far to assist the detection of binding sites at the genomic scale. RESULTS: FITBAR (Fast Investigation Tool for Bacterial and Archaeal Regulons) is a web service designed to identify new protein binding sites on fully sequenced prokaryotic genomes. This tool consists in a workbench where the significance of the predictions can be compared using different statistical methods, a feature not found in existing resources. The Local Markov Model and the Compound Importance Sampling algorithms have been implemented to compute the P-value of newly discovered binding sites. In addition, FITBAR provides two optimized genomic scanning algorithms using either log-odds or entropy-weighted position-specific scoring matrices. Other significant features include the production of a detailed genomic context map for each detected binding site and the export of the search results in spreadsheet and portable document formats. FITBAR discovery of a high affinity Escherichia coli NagC binding site was validated experimentally in vitro as well as in vivo and published. CONCLUSIONS: FITBAR was developed in order to allow fast, accurate and statistically robust predictions of prokaryotic regulons. This feature constitutes the main advantage of this web tool over other matrix search programs and does not impair its performance. The web service is available at http://archaea.u-psud.fr/fitbar.

UNLABELLED: BAGET (Bacterial and Archaeal Gene Exploration Tool) is a web service designed to facilitate extraction, by molecular geneticists and phylogeneticists, of specific gene and protein sequences from completely determined prokaryotic genomes. Upon selection of a particular prokaryotic organism and gene, two levels of visual gene context information are provided on a single dynamic page: (i) a graphical representation of a user defined portion of the chromosome centered on the gene of interest and (ii) the DNA sequence of the query gene, of the immediate neighboring genes and the intergenic regions each identified by a consistent color code. The aminoacid sequence is provided for protein-coding query genes. Query results can be exported as a rich text format (RTF) word processor file for printing, archival or further analysis. AVAILABILITY: http://archaea.u-psud.fr/bin/baget.dll.