This family carries twelve transmembrane regions. It does not have any characteristic nucleotide-binding-domains of the GxSGSGKST type. so it may not be an ATP-binding cassette transporter. However, it may well be a transporter of some description. ABC transporters always have two nucleotide binding domains; this has two unusual conserved sequence-motifs: 'KDhKxhhR' and 'LxxLP'.