Effector-dependent activation of truncated glmS ribozymes. (A) GlcN6P concentration-dependent responses of minimal glmS ribozymes (terminating after the P2 stem) are similar to that of a full-length ribozyme. Data were obtained using the B. subtilis P2 term (Fig. 6A) (C76 3′ terminus, open circles) and a B. cereus 201 glmS-derived variant terminating at G68 (filled circles). Data corresponding to the full-length B. subtilis 246 glmS ribozyme are shown for comparison (filled squares). Cleavage reactions included 100 mM MgCl2. (B) Effector selectivity of a minimal glmS ribozyme. An internally 32P-labeled P2 term ribozyme from B. subtilis was incubated in the absence (—) or the presence of 200 μ M GlcN6P or related compound, as indicated. Reactions contained 100 mM MgCl2 and were halted after 5 min at room temperature. Precursor (Pre) and the 5′ (5′ Clv) and 3′ (3′ Clv) cleavage products are indicated. NR represents no reaction. Compounds are abbreviated as follows: GlcN, glucosamine; GlcN6S, glucosamine 6-sulfate; Glc1P, glucose 1-phosphate; Glc6P, glucose 6-phosphate; Glc, glucose.
