Extended and Robust Protein Sequence Annotation over Conservative Nonhierarchical Clusters

Genome annotation is one of the most important issues in the genomic era. The exponential growth rate of newly sequenced genomes and proteomes urges the development of fast and reliable annotation methods, suited to exploit all the information available in curated databases of protein sequences and structures. To this aim we developed BAR+, the Bologna Annotation Resource.1 The basic notion is that sequences with high identity value to a counterpart can inherit the same function/s and structure, if available. As a case study we describe how the ATP-binding domain of the ABC transporters can be found and modeled in over 30,000 new sequences not annotated before. We also mapped into BAR+ all the ABC transporters listed in the Transporter Classification DataBase2 and found that within our environment annotation could be extended to another 256,866 sequences.