I've been looking through the files available at www.reactome.org along with some others but I only find images/pdfs of metabolic pathway diagrams. Where is the actual data these pathways are drawn from? I imagine there should be some kind of directed graph representation. I'm limited to freely available datasets, so unfortunately I'm not able to check out those such as KEGG.
http://www.reactome.org/download/index.html ?
Yes, those are the files I've been looking through and haven't found the pathway data I described. For example, if I look at the Human protein-protein interaction pairs file, it gives reactions as a format like REACT_27257.1. If I look at the Events in their Biopax format for humans, there is an entry for that reaction that simply has a comment with a link to the reactome website to view the pathway diagram. However, what I'm looking for is the actual data used to create that diagram.