2Department of Molecular Biology, Biological Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia; fax: (495) 939-4309; E-mail: email@example.com
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Received October 3, 2011; Revision received October 19, 2011
Cys2His2 (C2H2)-type zinc fingers are widespread DNA binding motifs in eukaryotic transcription factors. Zinc fingers are short protein motifs composed of two or three β-layers and one α-helix. Two cysteine and two histidine residues located in certain positions bind zinc to stabilize the structure. Four other amino acid residues localized in specific positions in the N-terminal region of the α-helix participate in DNA binding by interacting with hydrogen donors and acceptors exposed in the DNA major groove. The number of zinc fingers in a single protein can vary over a wide range, thus enabling variability of target DNA sequences. Besides DNA binding, zinc fingers can also provide protein–protein and RNA–protein interactions. For the most part, proteins containing the C2H2-type zinc fingers are trans regulators of gene expression that play an important role in cellular processes such as development, differentiation, and suppression of malignant cell transformation (oncosuppression).
KEY WORDS: zinc finger, DNA-binding protein, transcription, regulation of gene expression