An object of the present invention is to provide novel ribozyme systems capable of catalyzing tRNA acylation using various carboxylic acids as acyl donors and uses thereof. Disclosed is a ribozyme catalyzing tRNA acylation having a structure consisting of the RNA sequence represented by (formula 1): P1-Z.sub.1Z.sub.2Z.sub.3Z.sub.4(N.sup.1).sub.1(N.sup.1).sub.2 . . . (N.sup.1).sub.p--P2-(N.sup.2).sub.1(N.sup.2).sub.2 . . . (N.sup.2).sub.qY.sub.1Y.sub.2Y.sub.3(N.sup.3).sub.1(N.sup.3).sub.2N.sup.4- GGN wherein (N.sup.1).sub.1-(N.sup.1).sub.p each independently represent any monoribonucleotide of U, C, A and G; p represents 3 or 4; (N.sup.2).sub.1-(N.sup.2).sub.q each independently represent any monoribonucleotide of U, C, A and G; q represents 5 or 6; (N.sup.3).sub.1-(N.sup.3).sub.2 each independently represent any monoribonucleotide of U, C, A and G; N.sup.4 represents any monoribonucleotide of U, C, A and G; Z.sub.1-Z.sub.4 each independently represent C or G; Y.sub.1-Y.sub.3 each independently represent C or G; N represents a monoribonucleotide complementary to A or G; and P1 and P2 represent a domain consisting of any RNA sequence capable of having a stem-loop structure.