MetalMine: a database of functional metal-binding sites in proteins

Abstract

We present a new database called MetalMine that contains the classification of metal-binding sites derived from the structures of protein-metal-ion complexes. Metal-binding sites were automatically extracted from Protein Data Bank (PDB) structures, classified based on the protein domains in which the metal-binding sites are incorporated, and then manually curated. Tentative or artificial metal ion coordinations were excluded during this curation process. On the web pages of the database, the following information about metal-binding sites is presented in a hierarchical manner: the kind of metal ion, metal-binding site typically specified by the name of the protein, and each instance of metal-binding coordinates in the PDB structures. The database search engine currently supports the following two types of queries. First, given the PDB code of a protein–metal–ion complex, it provides a list of metal-binding sites incorporated in the structure file. Second, given an amino acid sequence as a query, it looks for matches with metal-binding residues in the Basic Local Alignment Search Tool (BLAST) sequence alignment. As of October 2009, MetalMine contained 412 classified entries of functional metal-binding sites, which we believe is the largest number of entries in databases available to the public.