Zinc fingers of the transcription factor IIIA (TFIIIA) type, in which zinc is co-ordinated by two cysteine and two histidine ligands (Cys2/His2), contain a length of helix packed against a β-hairpin. These zinc fingers comprise the wider range of structurally homologous proteins for which 1H chemical shifts are available. A number of key resonances have chemical shifts that are highly sensitive to tertiary structure and are conserved between these peptides. The high conservation of these fingerprint chemical shifts is correlated with the common global fold of Cys2/His2 zinc fingers. These chemical shifts are largely independent of primary structure and should facilitate NMR assignments for future zinc finger proteins, as well as provide a diagnostic signature for the characteristic Cys2/His2 zinc finger fold.
