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Your query returned 1 entry. 
Printable version
| EC | 4.6.1.25 | ||||||
| Accepted name: | bacteriophage T4 restriction endoribonuclease RegB | ||||||
| Reaction: | a [pre-mRNA]-containing guanosine-adenosine + H2O = a 5′ hydroxy-guanosine-[pre-mRNA fragment] + a [pre-mRNA fragment]-3′-adenosine-3′-phosphate (overall reaction) (1a) a [pre-mRNA]-containing guanosine-adenosine + H2O = a 5′ hydroxy-guanosine-[pre-mRNA fragment] + a [pre-mRNA fragment]-adenosine-2′,3′-cyclophosphate (1b) a [pre-mRNA fragment]- adenosine-2′,3′-cyclophosphate + H2O = a [pre-mRNAfragment]-3′-adenosine-3′-phosphate |
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| Other name(s): | RegB | ||||||
| Systematic name: | [pre-mRNA]-guanosine-adenosine 5′-hydroxy-guanosine-ribonucleotide-3′-[RNA fragment]-lyase (cyclicizing; [RNA fragment]-3′- adenosine -2′,3′-cyclophosphate-forming and hydrolysing) | ||||||
| Comments: | The enzyme from bacteriophage T4 cleaves early mRNAs between Ap and Gp at one specific specific GpGpApGp site, favouring their further transition to middle-phase mRNA. The activity is enhanced by Ribosomal S1 protein. The enzyme catalyses 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 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. | ||||||
| Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||
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