Figure 1.

T. cruzi ABC proteins. ABC proteins share a nucleotide-binding domain (NBD), displaying conserved sequences among organisms. A typical full-size ABC transporter presents, in addition to the two NBDs, two transmembrane domains, which could be rearranged in direct (TMD–NBD) or reverse (NBD–TMD) order. Half-size transporters have only a TMD and an NBD, assuming that they form dimers or oligomers to transport substrates across membranes. The standardized names of ABC proteins in subfamilies according to HUGO nomenclature are represented by the forth letter, followed by number. For example ABCA1 is subfamily A, member 1.