2.2 General features of higher-order nucleic acid structure
Polynucleotide chains are intrinsically flexible molecules and have the potential to form many different higher-order structures. Their flexibility derives from rotation around bonds in the sugar-phosphate backbone (Figure 3b). In vivo, the structures that form are obviously determined by both the proteins that synthesise the nucleic acid chains (polymerases) and the ancillary proteins that bind to and modify them. We will discuss these aspects of structure later in this unit. What drives the formation of these structures are the properties of the component nucleotides and the interactions between them in the form of base pairing and base stacking.