Figure 2. Schematic illustration of canonical regulation of transcription by Zur.

Zinc-bound Zur (right-hand panel; see below for further details) represses transcription by binding to specific DNA sequences (Zur boxes) in the promoter region of Zur-regulated genes and thus inhibits initiation of transcription. When cells are deprived of zinc, demetallated Zur has a dramatically reduced affinity for DNA, allowing transcription to occur.