Z-DNA: Difference between revisions

Line 5:

== Structure ==

Z-DNA <scene name='Sandbox_Z-DNA/B-z/7'>(default scene)</scene> can form ''invitro'' from B-DNA by raising negative super helical stress or under low salt conditions when deoxycytosine is 5-methylated. The formation of Z-DNA ''invivo'' is an energy requiring process. it forms behind a moving RNA polymerase ~~when it moves~~ through DNA double helix during transcription and is subsequently stabilized due to the generation of negative supercoils. Z-DNA is the first single crystal X-ray structure of a DNA fragment. It was crystallized as a self complementary DNA hexamer d(CG)<sub>3</sub> by Andrew Wang, Alexander Rich and their co-workers at MIT in 1979. <ref name = 'Rich'>PMID:12838348</ref><ref name ='Wang'>PMID:17485386</ref>

Z-DNA <scene name='Sandbox_Z-DNA/B-z/7'>(default scene)</scene> can form ''invitro'' from B-DNA by raising negative super helical stress or under low salt conditions when deoxycytosine is 5-methylated. The formation of Z-DNA ''invivo'' is an energy requiring process. It forms behind a moving RNA polymerase moving through a DNA double helix during transcription and is subsequently stabilized due to the generation of negative supercoils. Z-DNA is the first single crystal X-ray structure of a DNA fragment. It was crystallized as a self complementary DNA hexamer d(CG)<sub>3</sub> by Andrew Wang, Alexander Rich and their co-workers at MIT in 1979. <ref name = 'Rich'>PMID:12838348</ref><ref name ='Wang'>PMID:17485386</ref>

Whenever B-DNA transforms into Z-DNA two<scene name='Sandbox_Z-DNA/B-zjunction/7'> B-Z junctions </scene> form. The crystal structure of these junctions revealed<scene name='Sandbox_Z-DNA/Extruded/12'> two extruded bases</scene>, <scene name='Z-DNA/Extruded/2'>adenine</scene> and <scene name='Z-DNA/Extruded/3'>thymine</scene> at the junction. A crucial finding from this structure is that a right handed DNA can transform to a left handed DNA or vice versa by the disruption and extrusion of a base pair. It has also been suggested that the extruded base pairs at B-Z DNA junction may be sites for DNA modification.<ref>PMID:16237447</ref>

Navigation menu

Page actions

Page actions

Personal tools

Navigation

Search

Tools

@@ Line 5: / Line 5: @@
 == Structure ==
 <applet load='2acj' size='280' frame='true' align='left' caption=' B-Z DNA ' scene ='Sandbox_Z-DNA/B-z/7' />
-Z-DNA <scene name='Sandbox_Z-DNA/B-z/7'>(default scene)</scene> can form ''invitro'' from B-DNA by raising negative super helical stress or under low salt conditions when deoxycytosine is 5-methylated. The formation of Z-DNA ''invivo'' is an energy requiring process. it forms behind a moving  RNA polymerase when it moves through DNA double helix during transcription and is subsequently stabilized due to the generation of negative supercoils. Z-DNA is the first single crystal X-ray structure of a DNA fragment. It was crystallized as a self complementary DNA hexamer d(CG)<sub>3</sub> by Andrew Wang, Alexander Rich and their co-workers at MIT in 1979. <ref name = 'Rich'>PMID:12838348</ref><ref name ='Wang'>PMID:17485386</ref>
+Z-DNA <scene name='Sandbox_Z-DNA/B-z/7'>(default scene)</scene> can form ''invitro'' from B-DNA by raising negative super helical stress or under low salt conditions when deoxycytosine is 5-methylated. The formation of Z-DNA ''invivo'' is an energy requiring process. It forms behind a moving  RNA polymerase moving through a DNA double helix during transcription and is subsequently stabilized due to the generation of negative supercoils. Z-DNA is the first single crystal X-ray structure of a DNA fragment. It was crystallized as a self complementary DNA hexamer d(CG)<sub>3</sub> by Andrew Wang, Alexander Rich and their co-workers at MIT in 1979. <ref name = 'Rich'>PMID:12838348</ref><ref name ='Wang'>PMID:17485386</ref>
 Whenever B-DNA transforms into Z-DNA two<scene name='Sandbox_Z-DNA/B-zjunction/7'> B-Z junctions </scene> form. The crystal structure of these junctions revealed<scene name='Sandbox_Z-DNA/Extruded/12'> two extruded bases</scene>, <scene name='Z-DNA/Extruded/2'>adenine</scene>  and <scene name='Z-DNA/Extruded/3'>thymine</scene> at the junction. A crucial finding from this structure is that a right handed DNA can transform to a left handed DNA or vice versa by the disruption and extrusion of a base pair. It has also been suggested that the extruded base pairs at B-Z DNA junction may be sites for DNA modification.<ref>PMID:16237447</ref>