Figure 1

Structure of the HIF-1 Complex. The hypoxia inducible factor 1 complex (HIF-1) is a dimer composed of two proteins involved in hypoxic gene transactivation, HIF-1α and HIF-1β (ARNT). Dimerization between these two factors is mediated by the helix-loop-helix (HLH) and Per-ARNT-SIM domains, and DNA binding involves the basic (b-) region of the b-HLH domains. HIF-1 modulates transcription through its transactivation domains (TAD). Between amino acids 401 and 603, HIF-1α contains an oxygen-dependent degradation domain (ODD) which controls its degradation under normoxia [24]. Fig. 1