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What is the role of zinc in zinc finger transcription factors?

What is the role of zinc in zinc finger transcription factors?

The zinc-finger domain is one of the most frequently utilized DNA-binding motif found in eukaryotic transcriptional factors. The binding of a zinc-finger domain to its target site juxtaposes three base pairs on DNA to a few amino acids in the α-helix structure.

How do zinc finger proteins bind to DNA?

The zinc fingers recognize specific trinucleotide DNA sequences by insertion of several a-helices in the major groove of the DNA. The CCHH domains are organized in tandem, and the cooperative binding of a-helices contribute to the strength and specificity of the protein-nucleic acid interaction.

Can zinc fingers bind RNA?

Zinc finger proteins are generally thought of as DNA-binding transcription factors. However, certain classes of zinc finger proteins, such as CCCH zinc finger proteins, often function as RNA-binding proteins and regulate RNA metabolism4.

Where do transcription factors attach?

Transcription factors are a very diverse family of proteins and generally function in multi-subunit protein complexes. They may bind directly to special “promoter” regions of DNA, which lie upstream of the coding region in a gene, or directly to the RNA polymerase molecule.

What are zinc fingers used for?

This class of zinc fingers can have a variety of functions such as binding RNA and mediating protein-protein interactions, but is best known for its role in sequence-specific DNA-binding proteins such as Zif268 (Egr1).

What binds to zinc?

Common Zn2+ ligands found within proteins include cysteine (S), histidine (N), aspartate (O), and glutamate (O) residues. The ionization state of the thiol group of cysteine governs its ability to bind metals, including Zn2+.

How does zinc finger nuclease work?

Zinc-finger nucleases (ZFNs) are artificial restriction enzymes generated by fusing a zinc finger DNA-binding domain to a DNA-cleavage domain. Zinc finger domains can be engineered to target specific desired DNA sequences and this enables zinc-finger nucleases to target unique sequences within complex genomes.

Can RNA bind to DNA?

Simultaneous binding of DNA and RNA facilitates the assembly of RNA-tethered transcriptional complexes, allowing the recruitment of RNA-containing complexes to specific DNA loci.

What are transcription factor binding sites?

Transcription Factor Binding Sites (TFBSs) Transcription factors (TFs) are proteins with DNA binding activity that are involved in the regulation of transcription. Generally, TFs modulate gene expression by binding to gene promoter regions or to distal regions called enhancers.

Why do transcription factors bind to major groove?

Certain proteins bind to DNA to alter its structure or to regulate transcription (copying DNA to RNA) or replication (copying DNA to DNA). It is easier for these DNA binding proteins to interact with the bases (the internal parts of the DNA molecule) on the major groove side because the backbones are not in the way.

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. Zinc fingers often bind to a sequence of DNA known as the GC box.

How does zinc bind to proteins?

Cysteine residues are known to perform essential functions within proteins, including binding to various metal ions. In particular, cysteine residues can display high affinity toward zinc ions (Zn2+), and these resulting Zn2+-cysteine complexes are critical mediators of protein structure, catalysis and regulation.

What is the function of the zinc finger?

Zinc finger proteins are among the most abundant proteins in eukaryotic genomes. Their functions are extraordinarily diverse and include DNA recognition, RNA packaging, transcriptional activation, regulation of apoptosis, protein folding and assembly, and lipid binding.

How does zinc finger nucleases recognize specific DNA sequences?

Zinc finger nucleases (ZFNs) have the remarkable ability to (A) bind to a specific location in the double-stranded DNA, break the double-stranded DNA at that specific location and, if an endogenous repair template is provided, initiate homology-directed repair, restoring the integrity of the newly edited double- …

How does A protein bind to RNA?

RNA-binding proteins (often abbreviated as RBPs) are proteins that bind to the double or single stranded RNA in cells and participate in forming ribonucleoprotein complexes….Double-stranded RNA-binding motif.

Available protein structures:
Pfam structures / ECOD
PDBsum structure summary

What is zinc finger motif?

A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn2+) in order to stabilize the fold. It was originally coined to describe the finger-like appearance of a hypothesized structure from the African clawed frog (Xenopus laevis) transcription factor IIIA.

How many transcription factor binding sites are there?

There are approximately 2800 proteins in the human genome that contain DNA-binding domains, and 1600 of these are presumed to function as transcription factors, though other studies indicate it to be a smaller number.

What binds to the major groove?

Because it is rich in information, and because it is larger and shallower than the minor groove, most DNA-binding proteins bind in the major groove.

Are zinc fingers sequence specific?

The zinc-finger transcription factors are among the best understood families in terms of sequence-specific DNA binding.

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