Comparative Analyses of Hairpin and BaciUus subtMs RibonucleaseSubstrate Recognition P Ribozym s JSen by Escherichia coli

Previously, we reported that the substrate shape recognition of the EScherichia coli ribonuclease (RNase) P ribozyme depends on the eoncentration of magnesium ion in vitro. We additional]y examined the Bacillvs subtilts RNase P ribozyme and found that the B. subti1ts enzyme also required high mag"esium ion, aboye 10 mM, for cleavage of a hairpin substrate. The results of kinetic studies showed that the metal ion concentration affected both the catalysis and the affinity of the ribozymes toward a hairpin RNA substrate.