A
zinc finger is a small
protein structural motif that is characterized by the
coordination of one or more
zinc ions in order to stabilize the fold. Originally coined to describe the finger-like appearance of a hypothesized structure from
Xenopus laevis transcription factor IIIA, the zinc finger name has now come to encompass a wide variety of differing protein structures.
Xenopus laevis TFIIIA was originally demonstrated to contain zinc and require the metal for function in 1983, the first such reported zinc requirement for a gene regulatory protein.