Home  |  Contact

ENZYME entry: EC 4.6.1.25

Accepted Name
Bacteriophage T(4) restriction endoribonuclease RegB.
Reaction catalysed
A (pre-mRNA)-containing guanosine-adenosine + H(2)O <=> a 5' hydroxy-guanosine-(pre-mRNA fragment) + a (pre-mRNA fragment)-3'-adenosine-3'-phosphate
Comment(s)
  • The enzyme from bacteriophage T(4) cleaves early mRNAs between Ap and Gp at one specific specific GpGpApGp site, favoring their further transition to middle-phase mRNA.
  • The activity is enhanced by Ribosomal S1 protein.
  • The enzyme catalyzes a two-stage endonucleolytic cleavage.
  • The first reaction produces 5'-hydroxy-phosphooligonucletides and 3'-phosphooligonucleotides ending 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.
Cross-references
BRENDA4.6.1.25
EC2PDB4.6.1.25
ExplorEnz4.6.1.25
PRIAM enzyme-specific profiles4.6.1.25
KEGG Ligand Database for Enzyme Nomenclature4.6.1.25
IUBMB Enzyme Nomenclature4.6.1.25
IntEnz4.6.1.25
MEDLINEFind literature relating to 4.6.1.25
MetaCyc4.6.1.25

View entry in original ENZYME format
View entry in raw text format (no links)
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.-.-.-