The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intracellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the ABC1 subfamily. Members of the ABC1 subfamily comprise the only major ABC subfamily found exclusively in multicellular eukaryotes. The full transporter encoded by this gene may be involved in development of resistance to xenobiotics and engulfment during programmed cell death. [From RefSeq]

The ABCA3 gene is located on the short arm of chromosome 16, where it spans a length of 64 kb with its 33 exons.  The encoded ABCA3 protein contains 1704 amino acid residues and has a molecular mass of 19 kDa.  The protein belongs to the highly conserved ABC superfamily of transporters, members of which are involved in the active translocation of a variety of substrates across cell membranes.  The ABCA3 protein is predicted to contain four core domains arranged in two similarly structured halves.  Each half contains six transmembrane domains and a cytosolic ATP-binding cassette (ABC).  This cassette consists of three peptide motifs; Walker A, Walker B, and Walker C motifs.  Of these, the Walker C signature motif is unique to ABCA transporters.  The six transmembrane domains in each half of the protein are assumed to create collectively a channel within the membrane for the transportation of lipids.  The energy for the translocation is provided to by ATP hydrolysis facilitated by the ABC domain.  

More than 200 mutations in this gene have been identified in patients with interstitial lung disease.