Mediates transcriptional repression in response to zinc. Represses several genes, including SLC30A5, SLC30A10 and CBWD1, by binding to the zinc transcriptional regulatory element (ZTRE) (5'-C[AC]C[TAG]CC[TC]-N(0-50)-[GA]G[ATC]G[TG]G-3') found in the promoter region. May play a role in the control of ribosome biogenesis, regulating predominantly rRNA levels, as well as those of several ribosomal proteins, thus coordinating this highly zinc-demanding process with the available zinc supply. Belongs to the krueppel C2H2-type zinc-finger protein family.