construct, from the T7 promoter to the terminator, was PCR amplified
and used as a template for IVT according to the standard protocol.
For in vivo RNAs, total RNAs were extracted from E.
coli cells with the FastPure Total RNA Isolation Kit
(Vazyme). The cells were transformed with the pRAP co-expression vector
and induced with IPTG for at least 2 h before being harvested for
RNA isolation. For Northern blotting, total RNAs (2 μg per lane)
or IVT RNAs (0.1 μg per lane) were subjected to 1.2% formaldehyde
agarose gel electrophoresis. The RNAs were then transferred to the
nylon membrane and cross-linked to the membrane using a UV transilluminator
(254 nm). The membrane with immobilized RNAs was then incubated in
a 20 mL hybridization buffer containing 0.25 pmol/mL biotin-labeled
DNA probes (5′-biotin-GCTATTTTTGCGGGCTTGTAACCGCCCTCGGC-3′)
that targets the twister ribozyme. The biotin-labeled probes were
detected using a Chemiluminescent Nucleic Acid Detection Module Kit
(Thermo Scientific, USA). The results were visualized using the ChemiDoc
Touch imaging system (Bio-Rad).