This is the structure of an RNA pseudoknot (437D)

Pseudoknot cartoon

The hairpin stem, in blue and cyan, is hard to pick out because the duplex is A-form and short.
Show me the stem

Extrahelical bases

Non-Watson-Crick interactions stabilize tertiary structure:

	(C8-A12) Pairing with in the loop
	(G7-A24) A24 in lariat contacts G in a GC pair via its Hoogsteen face
	(C15-A23) A23 contacts C15 via base and sugar contacts
	(C10-G28) A Watson-Crick base pair in a non-traditional helical structure