What is zinc coordination?
What is zinc coordination?
Zinc is considered as a borderline metal, being coordinated by both the sulfur atom of cysteine and nitrogen atom of histidine (soft base ligands) or by carboxylate anions of aspartate and glutamate (hard base ligands).
How are zinc fingers so specific for a DNA sequence?
The binding of zinc finger is found to be distinct from many other DNA-binding proteins that bind DNA through the 2-fold symmetry of the double helix, instead zinc fingers are linked linearly in tandem to bind nucleic acid sequences of varying lengths.
Why is zinc colorless?
In the zinc case, the 3d level is completely full – there aren’t any gaps to promote an electron in to. Zinc complexes are also colourless. Simple tetrahedral complexes have four ligands arranged around the central metal ion. Again the ligands have an effect on the energy of the d electrons in the metal ion.
What is the coordination geometry around the zinc in zinc chloride?
2007 Schools Wikipedia Selection. Related subjects: Chemical compounds
| Zinc chloride | |
|---|---|
| Melting point | 275 °C (548 K) |
| Boiling point | 756 °C (1029 K) |
| Structure | |
| Coordination geometry | Tetrahedral, 4-coordinate, linear in the gas phase. |
Are zinc ions positive or negative?
Zinc most commonly forms positively charged cations with a charge of +2. Zinc will rarely form ions with a +1 charge but it will never form ions with a negative charge. As zinc is a metal, it generally forms metallic compounds with other metals.
Are zinc finger transcription factors?
Zinc finger proteins are the largest transcription factor family in human genome. The diverse combinations and functions of zinc finger motifs make zinc finger proteins versatile in biological processes, including development, differentiation, metabolism and autophagy.
Is zinc finger a transcription factor?
Why is zinc 2+ Colourless?
(i) Zinc has no unpaired electrons in has a stable fully filled d orbital its d orbital and state. Thus, due to absence of unpaired electrons, Zn2+ salts are colourless.
What are the coordinating amino acid residues and zinc ions highlighted by?
The coordinating amino acid residues and zinc ions (green) are highlighted. A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn 2+) in order to stabilize the fold. It was originally coined to describe the finger-like appearance of a hypothesized structure from
How many histidine residues are in the zinc finger motif?
Zinc finger. Cartoon representation of the Cys2His2 zinc finger motif, consisting of an α helix and an antiparallel β sheet. The zinc ion (green) is coordinated by two histidine residues and two cysteine residues.
What is the structure of the ribbon fold of zinc?
The zinc ribbon fold is characterised by two beta-hairpins forming two structurally similar zinc-binding sub-sites. The canonical members of this class contain a binuclear zinc cluster in which two zinc ions are bound by six cysteine residues.
How many histidine and cysteine residues are there in Zif268?
The zinc ion (green) is coordinated by two histidine residues and two cysteine residues. Cartoon representation of the protein Zif268 (blue) containing three zinc fingers in complex with DNA (orange).
