NEW PHOTOACTIVATABLE STRUCTURAL AND AFFINITY PROBES OF RNAS - SPECIFIC FEATURES AND APPLICATIONS FOR MAPPING OF SPERMINE BINDING-SITES IN YEAST TRANSFER RNAASP AND INTERACTION OF THIS TRANSFER-RNA WITH YEAST ASPARTYL-TRANSFER RNA-SYNTHETASE

Aryldiazonium salts are shown to be useful as phototriggered structural probes for RNA mapping as well as for footprinting of RNA/protein interaction. In particular the yeast tRNAAsp/aspartyl-tRNA synthetase complex is shown to involve the variable loop face and the concave side of the L-shaped nucleic acid bound to a lipophilic area of the enzyme. When chemically linked to spermine, the photoactive group cleaves RNA at polyamine binding sites ; 3-4 spermines have been located in the tRNAAsp, stabilizing the central part of the molecule in regions where two ribose-phosphate strands are close to each other. © 1990 Oxford University Press.