ENZYME entry: EC 4.6.1.24

Accepted Name

ribonuclease T1

Alternative Name(s)

Aspergillus oryzae ribonuclease

guanyloribonuclease

RNase N1

RNase N2

Reaction catalysed

[RNA] containing guanosine + H2O = an [RNA fragment]-3'-guanosine-3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA fragment]

Comment(s)

A family of related enzymes found in some fungi and bacteria.
The enzyme is specific for cleavage at the 3'-phosphate group of guanosine in single stranded RNA, and catalyzes a two-stage endonucleolytic cleavage.
The first reaction produces 5'-hydroxy-phosphooligonucletides and 3'-phosphooligonucleotides ending in Gp with 2',3'-cyclic phosphodiester, which are released from the enzyme.
The enzyme then hydrolyzes these cyclic compounds in a second reaction that takes place only when all the susceptible 3',5'-phosphodiester bonds have been cyclised.
The second reaction is a reversal of the first reaction using the hydroxyl group of water instead of the 5'-hydroxyl group of ribose.
The overall process is that of a phosphorus-oxygen lyase followed by hydrolysis to form the 3'-nucleotides.
Formerly EC 2.7.7.26, EC 3.1.4.8 and EC 3.1.27.3.

Cross-references

BRENDA

EC2PDB

ExplorEnz

KEGG Ligand Database for Enzyme Nomenclature

IUBMB Enzyme Nomenclature

MEDLINE

MetaCyc

Rhea expert-curated reactions

UniProtKB/Swiss-Prot

All UniProtKB/Swiss-Prot entries referenced in this entry, with possibility to download in different formats, align etc.

All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 4.6.1.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 4.6.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 4.-.-.-