Zinc fingers: conserved properties that can distinguish between spurious and actual DNA-binding motifs.

The zinc finger, one of the major structural motifs used for sequence specific DNA binding, has been identified in many regulatory proteins. By analogy, involvement in nucleic acid recognition has been implied for proteins that contain two cysteines and two histidines, spaced in accordance with the zinc finger motif. In this study we identify sequence dependent characteristics that are conserved in the DNA-binding zinc fingers and are probably required for a functional DNA-binding zinc finger. Examination of the conserved properties in view of the solved three dimensional structure of a zinc finger, confirms the importance of most of these properties. The absence of the identified physical-chemical characteristics from CCHH containing sequences of non-DNA binding proteins suggest that they can be used to distinguish between spurious and actual DNA binding zinc fingers.