RNase I degrades single-stranded RNA to nucleoside 3´ monophosphates
via 2´,3´ cyclic monophosphate intermediates by cleaving
between all dinucleotide pairs,2,3 unlike RNase A, which cleaves
only after cytosine and uridine. In addition, the enzyme is completely
inactivated by heating at 70°C for 15 minutes, eliminating the requirement
to remove the enzyme prior to many subsequent procedures.
Unit Definition: One unit of RNase I degrades 100 ng of E.
coli ribosomal RNA per second into acid-soluble nucleotides at
37°C under standard assay conditions.
Dilution and Storage Buffer: 50% glycerol containing 50 mM Tris-HCl
(pH 7.5), 100 mM NaCl, and 0.1 mM EDTA.
Quality Control: RNase I is free of detectable exo- and endodeoxyribonuclease