secondary structure of nucleic acid
secondary structure of nucleic acidthe configuration of a NUCLEIC ACID as a result of the folding of the PRIMARY STRUCTURE. Examples of secondary (helical) structure for double-stranded DNA include B-DNA, A-DNA and Z-DNA, which form due to HYDROGEN BONDS between complementary base pairs. See DNA(a). Double-stranded RNA and DNA-RNA hybrids generally adopt a secondary structure similar to the A-form. Single-stranded nucleic acid molecules, for example single-stranded RNA, can have secondary structure consisting of duplex and loop regions due to intra-strand COMPLEMENTARY BASE PAIRING. There can be various secondary structure motifs in nucleic acids, such as HAIRPINS, bubbles and bulges. Secondary structure of the molecule has implications for its stability, replication and function.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005