RNase I

RNase I is a nonspecific ribonuclease that hydrolyzes phosphodiester bond after all four bases.

Description:

· Only available RNase that cleaves the phosphodiester bond of all four bases.

· Degrades RNA to cyclic nucleotide monophosphates leaving a 5'-OH and 2'-, 3'-cyclic monophosphate.

· Prefers single-stranded RNA to double-stranded RNA.

· Produced from an overexpressing clone in E. coli (2).

· Contains no endonuclease or exonuclease activity toward DNA substrates.

· No need for boiling prior to use.

· Ideal for ribonuclease protection assays.

· Useful for mapping or quantitation of RNA by selective cleavage of single-strand regions.

Unit Definition: One unit is the amount of enzyme required to degrade 50% of [a-³³P] labeled RNA transcript mixed with 2 µg of yeast RNA in 30 min at 37^oC as detected by TCA precipitation.

Storage Conditions: Store at –20^oC.

Storage Buffer: 10 mM Tris-HCl (pH 8.0 at 22^oC), 200 mM NaCl, 50% glycerol.

Quality Control: All preparations are assayed for contaminating exonuclease and nonspecific endonuclease activities.

References:

1. Meador, J. III and Kennell, D. (1990) Gene 95, 1-7.

2. Meador, J. III et. al. (1990) Eur. J. Biochem. 187, 549.