Selenoproteins are a diverse group of proteins usually misidentified and 
misannotated in sequence databases. The presence of an in-frame UGA (stop) codon 
in the coding sequence of selenoprotein genes precludes their identification and 
correct annotation. The in-frame UGA codons are recoded to cotranslationally 
incorporate selenocysteine, a rare selenium-containing amino acid. The 
development of ad hoc experimental and, more recently, computational approaches 
have allowed the efficient identification and characterization of the 
selenoproteomes of a growing number of species. Today, dozens of selenoprotein 
families have been described and more are being discovered in recently sequenced 
species, but the correct genomic annotation is not available for the majority of 
these genes. SelenoDB is a long-term project that aims to provide, through the 
collaborative effort of experimental and computational researchers, automatic 
and manually curated annotations of selenoprotein genes, proteins and SECIS 
elements. Version 1.0 of the database includes an initial set of eukaryotic 
genomic annotations, with special emphasis on the human selenoproteome, for 
immediate inspection by selenium researchers or incorporation into more general 
databases. SelenoDB is freely available at http://www.selenodb.org.