Escherichia coli K-12 substr. MG1655 Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateMacromolecule ReactionsPolynucleotide-ReactionsRNA-ReactionstRNA-Reactions

EC Number:

Enzymes and Genes:
RNase BNInferred from experiment: rbn

Supersedes EC number:

Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.

Mass balance status: Balance undetermined; a substrate lacks a chemical formula

Enzyme Commission Primary Name: exoribonuclease II

Enzyme Commission Synonyms: ribonuclease II, ribonuclease Q, BN ribonuclease, Escherichia coli exo-RNase II, RNase II, exoribonuclease (misleading), 5'-exoribonuclease (misleading)

Enzyme Commission Summary:
Preference for single-stranded RNA. The enzyme processes 3′-terminal extra-nucleotides of monomeric tRNA precursors, following the action of EC ribonuclease P.

Citations: [Sporn69, Shimura78, Schmidt78, Nossal68 ]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reaction of [a tRNA precursor + H2O → a tRNA + a nucleoside 5'-monophosphate] (
i1: a tRNA precursor with a 5' extension and a long 3' trailer + H2O → a tRNA precursor with a 5' extension + a ribonucleoside 5'-monophosphate (

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:

Created 20-Aug-2010 by Shearer A, SRI International


Nossal68: Nossal NG, Singer MF (1968). "The processive degradation of individual polyribonucleotide chains. I. Escherichia coli ribonuclease II." J Biol Chem 243(5);913-22. PMID: 4867942

Schmidt78: Schmidt FJ, McClain WH (1978). "An Escherichia coli ribonuclease which removes an extra nucleotide from a biosynthetic intermediate of bacteriophage T4 proline transfer RNA." Nucleic Acids Res 5(11);4129-39. PMID: 364422

Shimura78: Shimura Y, Sakano H, Nagawa F (1978). "Specific ribonucleases involved in processing of tRNA precursors of Escherichia coli. Partial purification and some properties." Eur J Biochem 86(1);267-81. PMID: 350582

Sporn69: Sporn MB, Lazarus HM, Smith JM, Henderson WR (1969). "Studies on nuclear exoribonucleases. 3. Isolation and properties of the enzyme from normal and malignant tissues of the mouse." Biochemistry 8(4);1698-706. PMID: 5805304

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by Pathway Tools version 19.5 (software by SRI International) on Thu May 5, 2016, biocyc13.