Hydrogen-bonded single-stranded circles

Fig. 6. Electron micrographs of hydrogen-bonded single-stranded circles formed when purified linear heavy AAV single polynucleotide chains are exposed to annealing conditions. The arrows point to the projections observed on such single-stranded circles...

Fig. 14. Conformational map for helices with i to i-4 hydrogen bonding (variants of the a-helix). The shaded areas represent those conformations which allow acceptable hydrogen bonding. Conformations inside the area (marked by 1) enclosed by the line (as shown more distinctly in Fig. 13) are sterioally allowed for single-stranded helical polyglyoine. Only conformations lying inside both areas satisfy simultaneously all criteria. The positions of the right- and left-handed standard a-helices are shown by circles, those of the cu-helioes are shown by triangles (Leach et al., 1966b).

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