BHLH

Brief Introduction

• Basic helix–loop–helix (bHLH) transcription factors (TFs) constitute one of the largest families of transcription factors in three eukaryotic kingdoms.

Figure 1. Protein Structure of BGIOSGA030958

• The bHLH domain contains approximately 60 amino acids, with two functionally distinctive regions: the basic region and the HLH region. The basic region is located at the N terminus of the bHLH domain consisted of 15 amino acids and functions as a DNA-binding motif. The HLH region contains two amphipathic a helices with a linking loop of variable lengths; the amphipathic a helices of two bHLH proteins can interact, allowing the formation of homodimers or heterodimers. Outside of the conserved bHLH domain, these proteins exhibit considerable sequence divergence.
• bHLHs represent key regulatory components in transcriptional networks controlling a number of biological processes. They have been reported to function in light signaling, hormone signaling，wound and drought stress responses， symbiotic ammonium transport， shoot branching，the development of fruit, flower, root, microspore, trichome and stomata.