FEATURES

FAMILY

chordopoxvirinae mRNA-capping enzyme regulatory subunit family

DESCRIPTION

Also known as MCES_VACCW, D12L. Regulatory subunit of the mRNA cap enzyme which stabilizes the catalytic subunit and enhances its methyltransferase activity through an allosteric mechanism. Heterodimeric mRNA capping enzyme catalyzes the linkage of a N7-methyl-guanosine moiety to the first transcribed nucleotide (cap 0 structure), whereas the polymerase associated VP39 is responsible for a second methylation at the 2'-O position of the ribose (cap 1 structure)., The heterodimeric enzyme is also involved in early viral gene transcription termination and intermediate viral gene transcription initiation. Early gene transcription termination requires the termination factor VTF, the DNA-dependent ATPase NPH-I and the Rap94 subunit of the viral RNA polymerase, as well as the presence of a specific termination motif. Binds, together with RAP94, to the termination motif 5'-UUUUUNU-3' in the nascent early mRNA. Heterodimer of a catalytic and a regulatory subunit. Intrinsic methyltransferase activity of the catalytic subunit is weak and needs to be stimulated 30- to 50-fold by the regulatory subunit, which is itself catalytically inert.

EXTERNAL LINKS

D12L

mRNA-capping enzyme regulatory subunit

D12L

Molecular Synopsis