Internal-loops (also termed interior loops) in
RNA are found where the double stranded RNA separates due to no
Watson-Crick-Franklin base pairing between the
nucleotides
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules with ...
. Internal-loops differ from
Stem-loops as they occur in middle of a stretch of double stranded RNA. The non-canonicoal residues result in the double helix becoming distorted due to unwinding, unstacking and kinking.
Internal-loops can be classified as either symmetrical or asymmetrical, with some asymmetrical internal-loops, also known as bulges. Many important structural motifs are composed of internal loops such as
the C-loop,
the docking-elbow,
kink-turns (k-turn),
the right-angle,
the sarcin/ricin loops (also called bulged-G motifs),
the twist-up motif
and the UAA/GAN internal loop motif.
References
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See also
*
Stem-loop
*
Nucleic acid secondary structure
Nucleic acid secondary structure is the basepairing interactions within a single nucleic acid polymer or between two polymers. It can be represented as a list of bases which are paired in a nucleic acid molecule.
The secondary structures of bi ...
RNA splicing