We've just published a Open Access paper in Bioinformatics on an approach to annotate the region of ligand binding within a target protein. This has a lot of applications in the use of ChEMBL, in particular providing greater accuracy in mapping functional effects, improving ligand-based target prediction approaches, and reducing false positives in sequence/target searching of ChEMBL. Where next for this work - well annotating to a site-specific level would be a good thing to implement (think about HIV-1 RT with the distinct nucleoside and non-nucleoside sites).
Here's the abstract...
Availability: The PPDMs resource and curation interface is available at https://www.ebi.ac.uk/chembl/research/ppdms/pfam_maps
Source code is available at https://github.com/chembl/pfam_map_loader to demonstrate the integration process with the main schema of ChEMBL.