show all | hide all No of entries

Information on EC 4.6.1.20 - ribonuclease U2

for references in articles please use BRENDA:EC4.6.1.20
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
EC Tree
IUBMB Comments
The enzyme secreted by the fungus Ustilago sphaerogena cleaves at the 3'-phosphate group of purines, and catalyses a two-stage endonucleolytic cleavage. The first reaction produces 5'-hydroxy-phosphooligonucletides and 3'-phosphooligonucleotides ending in Ap or Gp with 2',3'-cyclic phosphodiester, which are released from the enzyme. The enzyme then hydrolyses 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.
Specify your search results
Select one or more organisms in this record: ?
Word Map
The enzyme appears in viruses and cellular organisms
Reaction Schemes
hide(Overall reactions are displayed. Show all >>)
[RNA] containing adenosine
+
=
an [RNA fragment]-3'-adenosine-3'-phosphate
+
a 5'-hydroxy-ribonucleotide-3'-[RNA fragment]
[RNA] containing guanosine
+
=
an [RNA fragment]-3'-guanosine-3'-phosphate
+
a 5'-hydroxy-ribonucleotide-3'-[RNA fragment]
Synonyms
Pleospora RNase, Purine specific endoribonuclease, Purine-specific ribonuclease, Purine-specific RNase, Ribonuclease (purine), ribonuclease U2, ribonuclease U2A, ribonuclease U2B, Ribonuclease U3, RNase U2, more
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
an [RNA fragment]-3'-adenosine-2',3'-cyclophosphate + H2O = an [RNA fragment]-3'-adenosine -3'-phosphate
show the reaction diagram
(1b)
-
-
-
an [RNA fragment]-3'-guanosine-2',3'-cyclophosphate + H2O = an [RNA fragment]-3'- guanosine-3'-phosphate
show the reaction diagram
(2b)
-
-
-
[RNA] containing adenosine + H2O = an [RNA fragment]-3'-adenosine-3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA fragment]
show the reaction diagram
(1) overall reaction
-
-
-
[RNA] containing adenosine = an [RNA fragment]-3'-adenosine-2',3'-cyclophosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA fragment]
show the reaction diagram
(1a)
-
-
-
[RNA] containing guanosine + H2O = an [RNA fragment]-3'-guanosine-3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA fragment]
show the reaction diagram
(2) overall reaction
-
-
-
[RNA] containing guanosine = an [RNA fragment]-3'-guanosine-2',3'-cyclophosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA fragment]
show the reaction diagram
(2a)
-
-
-
Select items on the left to see more content.