Z-DNA

Z-DNA is quite different from the right-handed forms.

Z-DNA is a relatively rare left-handed double-helix.

When the left version appears, the editor molecule jumps in, attaches itself to the Z-DNA, and alters the message being read out.

Z-DNA is one of the many possible double helical structures of DNA.

At the junction of B- and Z-DNA one pair of bases is flipped out from normal bonding.

After 26 years of attempts, Rich et al. finally crystallised the junction box of B- and Z-DNA.

In fact, Z-DNA is often compared against B-DNA in order to illustrate the major differences.

Crystal structure of a junction between B-DNA and Z-DNA reveals two extruded bases.

Z-DNA is thought to be one of three biologically active double helical structures along with A- and B-DNA.

Z-DNA's zigzag backbone is due to the C sugar conformation compensating for G glycosidic bond conformation.

The first domain to bind Z-DNA with high affinity was discovered in ADAR1 using an approach developed by Alan Herbert.

Crystallographic and NMR studies confirmed the biochemical findings that this domain bound Z-DNA in a non-sequence-specific manner.

It was named left-handed DNA, or Z-DNA, and molecular biologists dismissed it as a fluke, probably just molecular junk.

Segments of DNA where the bases have been chemically modified by methylation may undergo a larger change in conformation and adopt the Z-DNA.

Slide and shift are typically small in B-DNA, but are substantial in A- and Z-DNA.

A and B chromosomes are very similar, forming right-handed helices, while Z-DNA is a more unusual left-handed helix with a zig-zag phosphate backbone.

While no definitive biological significance of Z-DNA has been found, it is commonly believed to provide torsional strain relief (supercoiling) while DNA transcription occurs.

A-DNA and Z-DNA differ significantly in their geometry and dimensions to B-DNA, although still form helical structures.

Z-DNA can form a junction with B-DNA (called a "B-to-Z junction box") in a structure which involves the extrusion of a base pair.

At least three DNA conformations are believed to be found in nature, A-DNA, B-DNA, and Z-DNA.

He suggests that a small molecule that interferes with the E3L binding to Z-DNA could thwart the activation of these genes and help protect people from pox infections.

Negative supercoiling is also thought to favour the transition between B-DNA and Z-DNA, and moderate the interactions of DNA binding proteins involved in gene regulation.

The tertiary arrangement of DNA's double helix in space includes B-DNA, A-DNA and Z-DNA.

Z-DNA does not contain single base-pairs but rather a GpC repeat with P-P distances varying for GpC and CpG.

A comparison of regions with a high sequence-dependent, predicted propensity to form Z-DNA in human chromosome 22 with a selected set of known gene transcription sites suggests there is a correlation.