Single Minded Homolog 1 (SIM1)

SIM1 transcript was detected only in fetal kidney out of various adult and fetal tissues tested. Since the sim gene plays an important role in Drosophila development and has peak levels of expression during the period of neurogenesis, it was proposed that the human SIM gene is a candidate for involvement in certain dysmorphic features, abnormalities of brain development, and/or mental retardation of Down syndrome.SIM1 encodes a deduced protein with 766 amino acids and a calculated molecular mass of 85 kD. The human and mouse SIM1 proteins have 96% amino acid sequence identity. Human SIM1 shows 87.2% amino acid identity with SIM2 in its N-terminal half, which includes the conserved bHLH, PAS1, PAS2, and HST domains, and 18% identity in its C-terminal part, which contains a ser-rich region.