Adenine nucleotide translocases are mitochondrial membrane proteins encoded by a small dispersed multigene family. We have previously cloned cDNAs derived from the mouse adenine nucleotide translocase-1 and -2 genes (Ant1 and Ant2) and assigned the loci to mouse chromosomes 8 and X, respectively. Here we describe the genomic organization of the Ant2 gene and its regional map position on the X chromosome, which was determined through linkage analysis using an interspecific backcross between Mus musculus and Mus spretus inbred strains. Ant2 cosegregates with DXMit49 and DXMit50 and lies distal to Agtr2 in the proximal region of the mouse X chromosome. This map assignment further defines a region of conserved synteny between human Xq22-q25 and the mouse proximal X chromosome.