A: RNase I is a non-specific endoribonuclease from E. coli that cleaves single-stranded RNA (ssRNA) after every nucleotide, generating nucleoside
3′-monophosphates. It does not degrade DNA and has no detectable DNase activity.
A: RNase I preferentially cleaves single-stranded RNA.
A: No. RNase I does not require divalent cations such as Mg²⁺ or Mn²⁺ for activity. This makes it compatible with EDTA-containing buffers and flexible in various reaction conditions.
A: No. ScriptGuard™ RNase Inhibitor inhibits RNase A-family enzymes, not RNase I. RNase I belongs to a different enzyme class and remains fully active in its presence.
A: RNase I can be inactivated by:
- Treatment with 0.1% SDS.
- Heat inactivation at 70°C for 20 minutes in the presence of 5 mM DTT.
A: RNase I and RNase A differ in multiple ways:
- RNase I cleaves RNA after every nucleotide (GAUC), whereas RNase A cleaves specifically after pyrimidines (U and C).
- RNase I does not require metal ions, while RNase A also functions without them but has different substrate preferences.
- RNase I is not inhibited by RNase A-family inhibitors such as ScriptGuard™ RNase Inhibitor.
A: Yes. RNase I efficiently digests unprotected single-stranded RNA while leaving protected RNA fragments intact, making it suitable for RPA workflows.
