Fig 3. MAEL HMG-box domain binding to small RNAs.
A) MAEL HMG-box domain does not bind to ssRNA. B) However, it forms a complex with double-stranded (ds) RNA of identical sequence as dsDNASRY. C, D) MAEL HMG-box does not bind to small RNA hairpins. E) Only weak complex formation is observed with hairpin that has mismatches in the stem. F) But when the stem is perfectly base-paired, the binding is stronger and appears increased than that observed with dsRNA (B). G) Binding of MAEL HMG-box to substrate with multiple short hairpins is weak. H) However, binding to RNA 4WJ (sequence identical to DNA 4WJ) is strong and two complexes are formed. These observations indicate that MAEL HMG-box prefers to bind to substrates with continuous dsRNA helices longer than 6 base-pairs located near unstructured or perturbed RNA regions.