DNA-binding protein that regulates the transcription of several genes and is involved in heart development and limb pattern formation (PubMed:10079235). May bind to the core DNA motif of promoters (By similarity). Monomer. Homodimer (via the T-box); binds DNA as homodimer. Shuttles between the cytoplasm and the nucleus. Expressed exclusively in the developing heart and eye. Expression begins within a subset of cardioblasts at neurula stages and continues within the heart during morphogenesis at later tadpole stages. Within the heart tube, expressed in all but the most anterior domain, the bulbus cordis. The T-Box domain binds to double-stranded DNA.