title: Interaction of poly(X) with poly(U): alkali metal ion specificity suggests a four-stranded helix.
mesh_terms: D009690:Nucleic Acid Conformation; D011072:Poly U; D011119:Polynucleotides; D013329:Structure-Activity Relationship
chemical_list: D011119:Polynucleotides; C010304:poly(xanthylic acid); D011072:Poly U