G-四联体

G-四联体(英语:G-quadruplexG-tetradsG4-DNA)是一种由富含鸟嘌呤的核酸序列所构成的四股型态。含有经由胡斯坦(Hoogsteen)氢键维持稳定,并由鸟嘌呤以正方形方式排列而成的结构。在方形中央有一个单价阳离子(通常是[1]。这种结构可见于DNARNALNA(锁核酸)与PNA(肽核酸);根据形成四联体的各股的方向,可能有分子内(intramolecular)、双分子(bimolecular)或四分子(tetramolecular)等不同类型[2]

在四联体的结构中,我们可以根据四股的方向,将结构分为平行反平行英语Antiparallel (biochemistry)

Structure of a G-quadruplex. Left: a G-tetrad. Right: an intramolecular G-quadruplex
3D Structure of the intramolecular human telomeric G-quadruplex in potassium solution (PDB ID 2HY9). The backbone is represented by a tube. The center of this structure contains three layers of G-tetrads. The hydrogen bonds in these layers are represented by blue dashed lines.

注释

  1. ^ Campbell, Nancy H.; Neidle, Stephen. Chapter 4. G-Quadruplexes and Metal Ions. Astrid Sigel, Helmut Sigel and Roland K. O. Sigel (编). Interplay between Metal Ions and Nucleic Acids. Metal Ions in Life Sciences 10. Springer. 2012: 119–1134. doi:10.1007/978-94-007-2172-2_4. 
  2. ^ Bochman, Matthew L.; Paeschke, Katrin; Zakian, Virginia A. DNA secondary structures: stability and function of G-quadruplex structures. Nature Reviews Genetics 13. Nature Publishing Group. 2012: 770–780. doi:10.1038/nrg3296. 

参考文献

外部链接

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