Transcription factor IIIA contains several repeat sequences of the motif with two cysteine and two histidine residues as ligands to bind a zinc atom. In this movie, the N-terminal six fingers of Xenopus TFIIIA bound to 5S rRNA gene are shown. The structure is from 1TF6.pdb (ref. Nolte et al. PNAS v95, 2938).
The zinc finger motif was discovered from alignment of Cys..Cys..His..His binding to zinc, the residues between Cys and His forming a finger structure. You can read a review by Rhodes and Klug in Scientific American vol. 268, p. 32 (1993).
nomunak 4 years ago
How were ZFN discovered?
tzephon 4 years ago