The deduced 523-amino acid protein contains 12 predicted membrane-spanning domains with extracellular N and C termini. Between transmembrane domains 9 and 10, ZTL1 has a zinc-binding histidine-rich intracellular loop. ZTL1 shares 34% identity with ZNT1 (SLC30A1) over a 122-amino acid stretch, and it shares significant homology with several rodent zinc transporters. Northern blot analysis detected 2.0- and 5.0-kb transcripts in CaCo2 cell line RNA. RT-PCR of mouse tissues detected ubiquitous expression, with highest level in kidney and lowest level in liver.The deduced 765-amino acid protein has 15 predicted membrane-spanning domains and a calculated molecular mass of about 84 kD. Western blot analysis of the full-length protein expressed in HeLa cells indicated an apparent molecular mass of about 55 kD.