Gene expression in eukaryotes is dependent on the mRNA methyl cap which mediates 
mRNA processing and translation initiation. Synthesis of the methyl cap 
initiates with the addition of 7-methylguanosine to the initiating nucleotide of 
RNA pol II (polymerase II) transcripts, which occurs predominantly during 
transcription and in mammals is catalysed by RNGTT (RNA guanylyltransferase and 
5' phosphatase) and RNMT (RNA guanine-7 methyltransferase). RNMT has a 
methyltransferase domain and an N-terminal domain whose function is unclear; it 
is conserved in mammals, but not required for cap methyltransferase activity. In 
the present study we report that the N-terminal domain is necessary and 
sufficient for RNMT recruitment to transcription initiation sites and that 
recruitment occurs in a DRB 
(5,6-dichloro-1-β-D-ribofuranosylbenzimidazole)-dependent manner. The 
RNMT-activating subunit, RAM (RNMT-activating miniprotein), is also recruited to 
transcription initiation sites via an interaction with RNMT. The RNMT N-terminal 
domain is required for transcript expression, translation and cell 
proliferation.