Syn and anti nucleosides: Difference between revisions
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of course C and T take part in Z-DNA, although only in the anti- conformation |
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== Pyrimidine Nucleosides == | == Pyrimidine Nucleosides == | ||
<scene name='Syn_and_anti_nucleosides/Anti-uridine/1'>View</scene> of uridine in the anti configuration, the oxygen on <font color=orange>C-2</font> of uridine is projecting away from the furanose ring. <scene name='Syn_and_anti_nucleosides/Syn-cytidine/1'>View</scene> of cytidine in the syn configuration, the oxygen on <font color=orange>C-2</font> is projecting toward the furanose ring. This oxygen at the <font color=orange>C-2</font> position produces significant hinderance to the rotation of the pyrimidine about the glycosidic bond as shown in this <scene name='Syn_and_anti_nucleosides/Syn-cytidine2/1'>scene</scene>. The oxygen doubled bonded to the <font color=orange>C-2</font> invades the space of the hydrogen at C-2' and to a lesser extent the oxygen of the furanose ring. Since both pyrimidines found in DNA have an oxygen at the C-2 position, nucleosides and nucleotides of these pyrimidines only adopt the anti conformation and | <scene name='Syn_and_anti_nucleosides/Anti-uridine/1'>View</scene> of uridine in the anti configuration, the oxygen on <font color=orange>C-2</font> of uridine is projecting away from the furanose ring. <scene name='Syn_and_anti_nucleosides/Syn-cytidine/1'>View</scene> of cytidine in the syn configuration, the oxygen on <font color=orange>C-2</font> is projecting toward the furanose ring. This oxygen at the <font color=orange>C-2</font> position produces significant hinderance to the rotation of the pyrimidine about the glycosidic bond as shown in this <scene name='Syn_and_anti_nucleosides/Syn-cytidine2/1'>scene</scene>. The oxygen doubled bonded to the <font color=orange>C-2</font> invades the space of the hydrogen at C-2' and to a lesser extent the oxygen of the furanose ring. Since both pyrimidines found in DNA have an oxygen at the C-2 position, nucleosides and nucleotides of these pyrimidines only adopt the anti conformation and they do so even in Z-DNA. | ||
== 3D Images of Nucleotides == | == 3D Images of Nucleotides == | ||