We present the infrastructure for mapping publishers' metadata formats into a standardized TEI representation in the context of the EU PEER project. Initiated as an experiment to observe the consequence of large scale author manuscript deposit in publication repositories, the project led to the design and implementation of an information HUB (the PEER Depot) where all publishers' data (the author's manuscript and, when available, publishers' metadata) would be normalized so that they could be further uploaded to a series of trusted publication repositories to be put eventually in open access.