Zinc cluster

Yeast transcription factor GAL4 contains a binuclear zinc cluster in its DNA-binding domain... 

The zinc cluster regions ofGAL4 bind at the two ends of the enhancer element... 

DNA-binding site specificity among the C -zinc cluster family of transcription factors is achieved by the linker regions... 

Subsequently Stephen Harrison s group determined the x-ray structure of a PPRl-DNA complex and showed that the zinc cluster domain of PPRl and its mode of binding to DNA was very similar to that of GAL4, and that PPRl also dimerized through a coiled-coil region. However, the linker region... 

Dimerization of the Ce-zinc cluster transcription factors involves an a-helical coiled coil in the dimerization region. Coiled coils, often called leucine zippers, are also found in a large group of transcription factors that do not contain zinc. The leucine zipper is made up of two a helices in a coiled coil with every seventh residue leucine or some other large hydrophobic residue, such as isoleucine or valine. Leucine zipper transcription factors (b/zip) include factors characterized by heterodimerization, for example Fos and Jun. The a-helical DNA-binding motifs of the heterodimers recognize quite different base sequences and are continous with the a helices of the zipper. 

Reece, R.J., Ptashne, M. Determinants of binding-site specificity among yeast Ce zinc cluster proteins. Science 261 909-911, 1993. 

A direct catalytic conversion of esters, lactones, and carboxylic acids to oxazolines was efficiently achieved by treatment with amino alcohols in the presence of the tetranuclear zinc cluster Zn4(0C0CF3)60 as catalyst, essential for condensation and cyclodehydration reactions. For example, the use of (5)-valinol allowed the easy synthesis of oxazolines 125 and 126 in satisfactory yields <06CC2711>. A one-pot direct preparation of various 2-substituted oxazolines (as well as benzoxazoles and oxadiazoles) was also performed from carboxylic acids and amino alcohols (or aminophenols or benzhydrazide) using Deoxo-Fluor reagent <06TL6497>. 

Two hexanuclear zinc clusters are mentioned elsewhere in this Chapter, one in Section V.A.7 (on zinc(II) reactions) above, the other in Section VII.D (on supramolecular chemistry) below. 

Fig. 36. The three-dimensional structure of the binuclear zinc cluster of leucine aminopeptidase, as determined by X-ray crystallographic methods (Burley etai, 1990 S. K. Burley and W. N. Lipscomb, personal communication).

Zinc Clusters Class II Histone Lysine Methyl Transferases... 

Figure 13 Properties of some zinc cluster sites observed in zinc enzymes and metallothionein. The bridging Cys residues as well as their spacing are identified for (a) Schizosaccharomyces pombe Lysine methyltransferase Clr4, (b) Neurospora crassa Histone H3 methyltransferase DlM-5, (c) /S-domain of human metallothionem-2, and(d) /3-domain of sea urchin metallothionein MTA. The PDB numbers are respectively IMVH, 1 ML9, IMHU, and IQJL...

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