zinc-fingerhttp://www.oed.com/dictionary/zinc-finger_n%3Ftab%3Dmeaning_and_usezinc finger, n.
First published 1993; not fully revised

zinc fingernoun

Biochem.
  1. 1987–
    A finger-like loop of peptides enclosing a bound zinc ion at one end, usually part of a larger protein molecule (esp. one regulating transcription).
    1. [1985
      The repeats are thought to be extended DNA-binding ‘fingers’ linked by flexible joints, each having a zinc ion centre.
      EMBO Journal vol. 4 1613 (caption) ]
    2. 1987
      A 30-amino acid peptide, which corresponds to the second ‘zinc finger’ domain of transcription factor IIIA, has been synthesized.
      Proceedings of National Academy of Sciences U.S.A. vol. 84 4841
    3. 1988
      Zinc fingers are postulated to bind selectively to control regions of the genomic DNA which is destined to transcribe 5S RNA.
      BioFactors vol. 1 34/2

Originally published as part of the entry for zinc, n.

zinc, n. was first published in 1921; not fully revised.