Participates in the control of cell fate choice by uncommitted neuroectodermal cells in the embryo. Transcriptional repressor. Binds DNA on N-box motifs: 5'-CACNAG-3'. Transcription repression requires formation of a complex with a corepressor protein (Groucho). Forms homodimers (By similarity). The orange domain and the basic helix-loop-helix motif mediate repression of specific transcriptional activators, such as basic helix-loop-helix protein dimers. The C-terminal WRPW motif is a transcriptional repression domain necessary for the interaction with Groucho, a transcriptional corepressor recruited to specific target DNA by Hairy-related proteins.