The Transporter Classification Database: recent advances

Nucleic Acids Res. 2009 Jan;37(Database issue):D274-8. doi: 10.1093/nar/gkn862. Epub 2008 Nov 20.


The Transporter Classification Database (TCDB), freely accessible at, is a relational database containing sequence, structural, functional and evolutionary information about transport systems from a variety of living organisms, based on the International Union of Biochemistry and Molecular Biology-approved transporter classification (TC) system. It is a curated repository for factual information compiled largely from published references. It uses a functional/phylogenetic system of classification, and currently encompasses about 5000 representative transporters and putative transporters in more than 500 families. We here describe novel software designed to support and extend the usefulness of TCDB. Our recent efforts render it more user friendly, incorporate machine learning to input novel data in a semiautomatic fashion, and allow analyses that are more accurate and less time consuming. The availability of these tools has resulted in recognition of distant phylogenetic relationships and tremendous expansion of the information available to TCDB users.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Artificial Intelligence
  • Databases, Protein*
  • Membrane Transport Proteins / chemistry
  • Membrane Transport Proteins / classification*
  • Membrane Transport Proteins / genetics
  • Phylogeny
  • Sequence Homology, Amino Acid


  • Membrane Transport Proteins