The in vitro DNA binding activity of the Arabidopsis Tag1 transposase (TAG1) was characterized to determine the mechanism of DNA recognition. In addition to terminal inverted repeats, the Tag1 element contains four different subterminal repeats that flank a transcribed region encoding a 729-amino acid protein. A single site-specific DNA binding domain is located near the N terminus of TAG1, bet...

Two homologous transcription factors, CueR and GolS, that belong to the MerR metalloregulatory family are responsible for Salmonella Cu and Au sensing and resistance, respectively. They share similarities not only in their sequences, but also in their target transcription binding sites. While CueR responds similarly to Au, Ag, or Cu to induce the expression of its target genes, GolS shows highe...

A new macrobicyclic ligand has been prepared, and it is shown to bind Zn(2+) on the inside. The ligand consists of a triamido(amine) motif to coordinate the metal ion and a narrow, hydrophobic channel above the metal binding site.

apotransferrin (apo tf)  in 0.1 m n-(2hydroxyethyl)piperazine-n2-ethanesulfanic acid at 25 ˚c  and ph 7.4 has been titrated with acidic solution of tb3+. the binding of tb3+ at  the two specific metal-binding sites of transferrin was followed from the changes in the difference uv spectra at 245 nm. the molar absorptivity per binding site for tb3+-tf is 22,500 ± 1000 m-1cm-1. to determine the tb...

the interaction of hgh with some metal ions ( ) at 27°c in nac1 solution, 50 mm was studied using isothermal titration calorimetry. there is a set of three identical and non-interacting binding sites for binding of all these metal ions, expect . the intrinsic association equilibrium constants () are not very different for  and , and also their molar enthalpies of binding (kj/mol for  and  kj/mo...

Almost all naturally occurring metalloproteases are monozinc enzymes. The zinc in any number of zinc metalloproteases has been substituted by some other divalent cation. Almost all Co(II)- or Mn(II)-substituted enzymes maintain the catalytic activity of their zinc counterparts. However, in the case of Cu(II) substitution of zinc proteases, a great number of enzymes are not active, for example, ...

Class I cyclic nucleotide phosphodiesterases (PDEs) share a catalytic domain containing 18 invariant residues. In cGMP-binding cGMP-specific PDE (PDE5), we showed previously that point mutation of nine of these profoundly decreases k(cat) when the assay is conducted in the presence of Mg(2+); seven of these are in the prototypical metal-binding motifs A and B (HX(3)HX(n)()E) that we identified ...

Protein geranylgeranyltransferase type-I (GGTase-I) transfers a geranylgeranyl group from the prenyl donor geranylgeranyl diphosphate (GGPP) to the cysteine residue of substrate proteins containing a C-terminal CaaX-motif (a sequence motif of proteins consisting of an invariant Cys residue fourth from the C-terminus). The GGTase-I heterodimer contains one atom of zinc, and this metal is require...