RNase R is a highly efficient exoribonuclease derived from E. coli that digests linear RNA in a 3’-to-5’ direction, while leaving lariat RNA, circular RNA, and certain structured RNAs intact. This unique specificity makes RNase R an essential tool for studying alternative splicing, gene expression, and RNA structure.
Unlike other RNases, RNase R does not degrade circular RNA, lariat RNA, or double-stranded RNA with short 3’ overhangs (<7 nucleotides). Most cellular RNAs, including mRNA, rRNA, and other linear RNA species, are completely digested, with the exception of tRNAs, 5S RNA, and intron lariats.