Transcriptional repressor of a subset of early mesodermal genes including myod1 and t/bra. Binds DNA on N-box motifs: 5'-CACNAG-3'. Acts as a negative regulator of myogenesis, mediating Notch signaling to repress expression of myod1 (By similarity). Transcription repression requires formation of a complex with a corepressor protein of the Groucho/TLE family. Interacts with the bHLH protein hes2, and binds DNA in the form of a heterodimer with the bHLH protein hey1/hrt1. Interacts with the bHLH protein hes6; this interaction may inhibit the transcriptional repressor activity (By similarity). Has a particular type of basic domain (presence of a helix-interrupting proline) that binds to the N-box (CACNAG), rather than the canonical E-box (CANNTG). The bHLH, as well as cooperation between the central Orange domain and the C-terminal WRPW motif, is required for transcriptional repressor activity. The C-terminal WRPW motif is a transcriptional repression domain necessary for the interaction with Groucho/TLE family members, transcriptional corepressors recruited to specific target DNA by Hairy-related proteins.