Testis ACE is an isozyme of angiotensin-converting enzyme (ACE) made by male germ cells. These cells recognize a small intragenic promoter which contains a positive regulatory element, TCTTAT, at position -32. A probe containing this element was gel shifted to an identical location by rat testis and rat liver nuclear extracts; formation of the complex was blocked by anti-TATA binding protein antibody. Recombinant TATA binding protein recognized the testis ACE TCTTAT motif as well as a probe containing the consensus TATA motif. Mice transgenic for testis ACE promoter constructs containing either the wild type testis ACE motif or a consensus TATA sequence expressed a reporter gene at high levels only within the testis. These data suggest that the testis ACE motif TCTTAT is a non-consensus TATA, but is not responsible for the highly restricted pattern of testis ACE gene expression.