Zinc-finger motif

TFIIIA has nine zinc fingers, but other proteins have anything from one to more than 60 zinc finger motifs within their sequence. 

It has also been possible to determine the x-ray structures of classic zinc finger motifs from several proteins bound to specific DNA fragments. We will here describe one such structure containing three zinc fingers from a mouse protein, Zif 268, which is expressed at an early developmental stage of the mouse. Nikola Pavletich and Carl Pabo at the Johns Hopkins University School of Medicine, Baltimore, determined the x-ray structure to 2.1 A resolution of a recombinant polypeptide derived from Zif 268 bound to a 10-base... 

The finger region of the classic zinc finger motif interacts with DNA... 

The 12 residues between the second cysteine zinc ligand and the first histidine ligand of the classic zinc finger motif form the "finger region". Structurally, this region comprises the second p strand, the N-terminal half of the helix and the two residues that form the turn between the p strand and the helix. This is the region of the polypeptide chain that forms the main interaction area with DNA and these interactions are both sequence specific. 

Proteins with the helix-turn-helix or leucine zipper motifs form symmetric dimers, and their respective DNA binding sites are symmetric palindromes. In proteins with the zinc finger motif, the binding site is repeated two to nine times. These features allow for cooperative interactions between binding sites and enhance the degree and affinity of binding. 

Hashimoto, T., Nakano, Y., Morinaga, T., and Tamaoki, T. (1992). A new family of homeobox genes encoding multiple homeodomain and zinc finger motifs. Mech. Dev. 39 125-126. 

Figure 12.14 (Left) Schematic representation of tandemly repeated zinc finger motif with their tetrahedrally coordinated Zn2+ ions. Conserved amino acids are labelled, and the most probable DNA-binding side chains are indicated by balls (from Klug and Rhodes, 1988). (Right) A ribbon diagram of a single zinc finger motif in a ribbon diagram representation. (From Voet and Voet, 2004. Reproduced with permission from John Wiley Sons., Inc.)...

Figure 2. Structural and functional domains of PARP-1. PARP-1 has a highly conserved structural and functional organization including (1) an N-terminal DNA binding domain with two Cys-Cys-His-Cys zinc finger motifs (FI and Fll), (2) a nuclear localization signal (NLS), (3) a central automodification domain containing a BRCT ( BRCAl C-terminus-like ) protein-protein interaction motif, and (4) a C-terminal catalytic domain with a contiguous 50 amino acid sequence, the PARP signature motif, that forms the active site...

Kojima K, Kaneda K, Yoshida C, Dansako H, Fuji N, Yano T, Shinagawa K, Yasukawa M, Fujita S, Tanimoto M (2003) A novel fusion variant of the MORF and CBP genes detected in therapy-related myelodysplastic syndrome with t(10 16)(q22 p 13). Br J Haematol 120 271—273 Koken MH, Saib A, de The H (1995) A C4HC3 zinc finger motif. C R Acad Sci 111 318 733-739 Korzus E, Torchia J, Rose DW, Xu L, Kurokawa R, Mclnemey EM, Mullen TM, Glass CK, Rosenfeld MG(1.9 98) Transcription factor-specific requirements for coactivators and their acetyltransferase functions. Science 279 703—707... 

Su(var)3-9 in the yeast two-hybrid interaction assay and increase the Su(var)3-9-mediated H3K9 methylation on autosomes and the male X chromosome. Su(var)3-7, contains seven widely spaced zinc-finger motifs, is involved in the recruitment of Su(var)3-9 (Schotta et al, 2002 Delattre et al, 2004). 

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