<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Motifs in DNA- and RNA-binding proteins whose amino acids are folded into a single structural unit around a zinc atom. In the classic zinc finger, one zinc atom is bound to two cysteines and two histidines. In between the cysteines and histidines are 12 residues which form a DNA binding fingertip. By variations in the composition of the sequences in the fingertip and the number and spacing of tandem repeats of the motif, zinc fingers can form a large number of different sequence specific binding sites.</n0:def-definition><n0:def-source>MSH2001</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>One of three structural motifs observed in DNA binding domains of zinc proteins. Domains in DNA- and RNA-binding proteins that contain amino acids which are folded into a single structural unit around a zinc atom that links two cysteines and two histidines. Each finger is postulated to recognize a specific sequence of about five nucleotide pairs. Originally identified in the TFIIIA transcription factor, it is also known as the C2H2 zinc finger.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>