Global transcriptional regulator involved in zinc homeostasis. Represses the transcription of at least 32 genes, including genes involved in zinc homeostasis, by binding to promoter sequences that contain a conserved 26 bp palindrome, in the presence of zinc. Binds 2 Zn(2+) ions per subunit. Three distinct zinc binding-sites were identified in the crystal structure, but the exact biological function of the third site remains to be determined. It could be an artifact of crystallization. Homodimer. Induced by zinc. Repressed by SmtB in the absence of zinc. The N-terminal domain binds DNA and the C-terminal domain is involved in metal-binding and dimerization. Belongs to the Fur family.