Capping enzyme
- OMIM: 603 512
- UniProt: O60942
The mRNA - capping enzyme (CE) is a previously provided by two enzymes in eukaryotic cells, the mRNA during transcription with a protective group of molecules, the so-called 5 'cap structure. Specifically, the CE brings to a Guanylylrest on the mRNA, which is later methylated. For this, two reaction steps are required, which are catalyzed by two different protein domains on the CE enzyme. It is a bifunctional enzyme. In humans four CE isoforms are known to occur in different tissue types and have partially lost their enzymatic activity.
CE is part of the so-called capping complex which formed after dissociation of the preinitiation complex after its separation from the promoter, and, inter alia, RNA polymerase II and contains the two capping enzymes.