Gene Ontology Help

mRNA capping enzyme complex Overview

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code.


Summary
Catalyzes the first step in mRNA cap formation. Consists of two subunits: an RNA 5'-triphosphatase (RTPase) and GTP:mRNA guanylyltransferase (GTase). The GTase subunit (CEG1) binds to the phosphorylated carboxyl-terminal domain of the largest subunit (CTD-P) of RNA polymerase II, coupling capping with transcription. CEG1 bound to the CTD-P is inactive unless allosterically activated by interaction with the RTPase subunit (CET1). CET1 removes the gamma-phosphate from the 5' end of the RNA substrate to leave a diphosphate end. CEG1 subsequently transfers the GMP moiety of GTP to the 5' end of RNA via an enzyme-GMP covalent reaction intermediate to form the structure GpppN1-.mRNA.
GO Slim Terms

The yeast GO Slim terms are higher level terms that best represent the major S. cerevisiae biological processes, functions, and cellular components. The GO Slim terms listed here are the broader parent terms for the specific terms to which this gene product is annotated, and thus represent the more general processes, functions, and components in which it is involved.

ion binding, ligase activity, nucleotidyltransferase activity, transferase activity, mRNA processing