A ribozyme is disclosed wherein the composition of the catalyst core sequence is comprised by two or more independent sequences and wherein catalyst activity is dependent upon the presence and association by hybridization of said components and a catalytically active conformation is assumed by hybridization with a target nucleic acid sequence comprising a sequence suitable for catalytic action. So long as essential and conversed bases are comprised by each of the individual, non-target strands, no sequence alone comprises the ribozyme or possesses catalytic activity. The target sequence of catalytic action and one or more of the sequences each comprising essential and conserved bases possessing catalytic activity may be consecutively associated. The ribozyme finds utility in both diagnostic and therapeutic applications. Generation of a surrogate template for direct detection or amplification is conditioned upon an active catalytic conformation of the ribozyme.
