The adenine nucleotide translocase（ANT） family of proteins are the most abundant inner membrane proteins of the mitochondrion.They are responsible for the transport of adenine nucleotides across the inner mitochondrial membrane

importing ADP for oxidative phosphorylation and exporting ATP to the cytosol.In this paper

RT-PCR and rapid amplification of cDNA ends（RACE） methods were used for the isolation of the whole cDNA of ant2 gene（GenBank accession number: FJ591153） from rainbow trout Oncorhynchus mykiss.Sequence analysis reveals a 1 276 bp cDNA containing 66 bp 5′-UTR

316 bp 3′-UTR and 894 bp ORF encoding 297 amino acids.It also has three conserved domains of mitochondrial carrier proteins and three transmembrane helixes.ANT2 shows extensive similarities to the known ADP/ATP translocase polypeptides

and the similarity is about 90% between vertebrates.Homology modeling shows that rainbow trout ANT2 protein has the same cavity structure with the ADP/ATP carrier

chain A of cattle.