 Welcome to this RIA tutorial. In this tutorial, you are going to discover the RIA knowledge base, its content and an overview of its website. What is RIA and what data is available? RIA is an expert curated and non-redundant resource of biochemical reactions. It describes biochemical transformations in a computationally tractable manner. More precisely, RIA describes enzyme catalyzed reactions mainly involving small molecules such as caffeine in this example. But it also describes enzyme catalyzed reactions involving macromolecules such as proteins, nucleic acids or polymers. As an example, we see here an enzyme catalyzed reaction leading to the methylation of mRNA. RIA also describes transport reactions which are catalyzed by enzymes. The example we see here shows the transport of arsenite into the cell and out of it, catalyzed by an ATPase. What are the key features of RIA? RIA is curated by experts based on the peer-reviewed scientific literature. Curators have gone through more than 14,000 publications and used them to annotate and describe RIA reactions in detail. The reaction participants are described using the KB resource for small chemical compounds. Where KB holds different representations of the same molecule at different pH values, the convention adopted by RIA is to represent the major species of chemical compounds, which is the one at pH 7.3. RIA includes the IUBMB enzyme nomenclature and classification. This classification is maintained by the International Union of Biochemistry and Molecular Biology. The protein knowledge-based Uniprot KB uses RIA as the standard for annotation, representation and searchability of enzyme catalyzed reactions. When available, RIA provides a link to related proteins in Uniprot KB. For example, this reaction is linked to five Uniprot entries, which actually describe two different proteins from three different species. Note that not all RIA reactions are linked to enzyme sequences in Uniprot KB. Making the links is an ongoing and collaborative process between RIA and Uniprot curators. Now let's discover the RIA website. In the center of the homepage, there is the query box. We will focus on different ways of searching RIA in another tutorial. For now, we will retrieve all RIA reactions simply by hitting the search button with an empty query and will use the result list to highlight some of the features of the RIA website, including how to filter, configure and download results. We see that more than 13,000 reactions have been curated in the database. Reactions are broken down and can be filtered by reaction type. Another filter allows us to browse through reactions by enzyme classification, also called EC number. More than half of the curated reactions have been classified and are therefore linked to an EC number. All the numbers shown here will of course change in future releases, as the database is updated. To find all proteins in the Uniprot knowledge base that are linked to the RIA reactions shown in our result page, we can click on this button. We can customize our table of results by adding a column for the PubMed ID, for example. This allows us to access the publications reviewed by the RIA curators to annotate the reactions. We click Save and see the PubMed column appear in the table. We can now download our result table in different formats, for example as a type separated file that reflects the column settings we have just made. The link that allows us to reproduce our personalized result table can be shared to our colleagues by using this button. Last but not least, let's go through the links that are available from the top of every page on the RIA website. The first one allows to perform a substructure search. We can obtain a set of molecules corresponding to kebby compounds that contain our query structure and that participate in RIA reactions. After clicking on Retrieve and ID mapping, we can enter a list of RIA identifiers and retrieve the corresponding reactions. The list of identifiers from other databases such as ecocyc, metasych, reactome or keg or chemical compound identifiers can also be submitted to obtain the corresponding RIA reactions. Using the RIA sparkle endpoint, we can, using a standardized query language, query and combine data from various sources that offer a similar service. For example, RIA, kebby and uniprot. All data in RIA is freely available and can be downloaded from our FTP site in different formats. We encourage you to have a look at our help pages and very importantly to contact us if you have any question or comment that the help pages cannot answer. We greatly appreciate any feedback, be it bug reports, usability issues or other suggestions. Also have a look at our other tutorials to get started. Thank you very much for your attention.