The zinc uptake regulator (Zur) gene is a bacterial gene that codes for a transcription factor protein involved in zinc homeostasis. The protein is a member of the ferric uptake regulator family and binds zinc with high affinity. It typically functions as a repressor of zinc uptake proteins via binding to characteristic promoter DNA sequences in a dimer-of-dimers arrangement that creates strong cooperativity. Under conditions of zinc deficiency, the protein undergoes a conformational change that prevents DNA binding, thereby lifting the repression and causing zinc uptake genes such as ZinT and the ZnuABC zinc transporter to be expressed.