Gene

SUPERFAMILY

Biology

Solute carrier family

Homology modeling

Receptor

Biochemistry

Computational biology

Genetics

Sequence homology

Transporter

Homology (biology)

Enzyme

Transmembrane domain

Peptide sequence

Transmembrane protein

ATP-binding cassette transporter

FEBS Letters

Members of the ATP-binding cassette (ABC) transporter superfamily translocate a broad spectrum of chemically diverse substrates. While their eponymous ATP-binding cassette in the nucleotide-binding domains (NBDs) is highly conserved, their transmembrane domains (TMDs) forming the translocation pathway exhibit distinct folds and topologies, suggesting that during evolution the ancient motor domains were combined with different transmembrane mechanical systems to orchestrate a variety of cellular processes. In recent years, it has become increasingly evident that the distinct TMD folds are best suited to categorize the multitude of ABC transporters. We therefore propose a new ABC transporter classification that is based on structural homology in the TMDs.

Structural and functional diversity calls for a new classification of ABC transporters